People have learned their lesson.

We've been told that so many times since the near-death experiences of the financial crisis. Bankers and regulators have flipped roles: Now it's the bankers who are cautious and their overseers who are aggressive.

Details of JPMorgan Chase's multibillion-dollar trading loss — brought to light by a riveting and devastating report from the Senate Permanent Subcommittee on Investigations — demonstrate what a sham that is. Bankers aren't acting cautious and chastened. Risk managers aren't in the ascendance on Wall Street. Regulators remain their duped and docile selves.

What we now know about the incident is that, as the cliché has it, the cover-up was worse than the crime. The losses out of the London office weren't enough to take down the bank. But as they were building, JPMorgan traders fiddled with risk measures and valuations. The bank's risk managers defended the traders and pooh-poohed the flashing red signals. The bank gave incorrect information to its regulator. Top executives then made misleading statements to shareholders and the public. All the while, the regulator served its typical role of house pet.

As JPMorgan got into trouble, traders and the responsible executives treated the valuation of trading positions, made up of derivatives, as a puppet made to do what they wanted. The traders pulled on this calculation or that to change the way they were valuing the position to reduce the losses.

Ina Drew, the head of the bank's chief investment office, referring to how the positions were calculated, asked an underling if he could "start getting a little bit of that mark back." She then asked if he could "tweak at whatever it is I'm trying to show." She might believe it is exculpatory that she prefaced the comment by saying to do it "if appropriate" and that the tweak should come with "demonstrable data," but any idiot working for her would know exactly what she meant: Create some rationale to manipulate the valuations to make things look better than they really are.

This discussion did not make it into the bank's internal report on the incident from January. Imagine that.

Yes, Ms. Drew was ousted. But her actions show that what financial executives do postcrisis when faced with trouble is no different than what they did precrisis. In testimony on Friday, in a quiet voice, she deflected blame up to Dimon and down to her traders, claiming she was kept in the dark.

The Senate report makes it clear that JPMorgan misled shareholders and the public, particularly on its April 13, 2012 conference call.

That call, which makes up a particularly damning portion of the Senate report, featured a haughty Jamie Dimon famously dismissing the problem as a "tempest in a teapot."

Of course, it was no such squall. On the call, the chief financial officer at the time, Douglas L. Braunstein, made a number of what appear to be misleading statements about the trades. Braunstein said the trading decisions were made on a very long-term basis, when in fact the traders were shuffling positions almost daily in order to make profits and then to disastrously "defend" their positions from further losses. Braunstein reassured investors and analysts on the call that the trades were vetted by the firm's top risk managers, when they were not (though top officials, including Dimon, knew about repeated risk-measure breaches).

This means "there was risk oversight" for the office that made the trades, and the trading "positions needed to comply with limits," a JPMorgan spokesman, Joseph Evangelisti, said. "We were not aware at the time of all the deficiencies in the risk organization" of the trading group.

On the conference call, Braunstein also said that the trades were "fully transparent to the regulators," but, in fact, watchdogs didn't receive any regular reporting of the positions and only received specific information just days before the call.

"What Doug said was accurate," Evangelisti said. "No one in senior management at that time believed there was a larger problem in the context of the firm's size and scale."

In JPMorgan's internal report, the call receives scant attention. In testimony before Sen. Carl Levin, the Michigan Democrat who heads the Senate subcommittee, Braunstein fell back on the explanation that he was saying what he believed at the time.

Braunstein wasn't available for comment, according to the bank.

Maybe regulators will think it notable that the chief financial officer of JPMorgan misled shareholders in his first extensive comments about the trading losses. Don't hold your breath.

I don't even expect much to come out of the evidence that the bank misled regulators. The bank stopped giving its regulator, the Office of the Comptroller of the Currency, important information. At one point, the bank told the agency that it was reducing the size of its positions when it was actually increasing it, according to the Senate report.

Despite JPMorgan's smoke screens, the regulators deserve the public humiliation they have received. They were alerted to risk-measure breaches that should have warned them of problems. By April 30, 2012, just weeks after the trading debacle came to light and before any serious investigation, the Office of the Comptroller of the Currency declared the matter closed, according to internal minutes from a meeting. (At Friday's hearing, officials from the agency disputed that it was, in fact, closed.)

So, yeah, people have learned their lessons, the real lessons of the financial crisis. JPMorgan repeated the same misdeeds that other banks successfully pulled off at the height of the financial crisis: mismarking portfolios of assets and misleading the public. This was condoned by regulators. Regulators and prosecutors have been averting their eyes for years from rotted bank assets and rotted bank morals; why would JPMorgan expect any different reaction in this case?

Dimon and JPMorgan executives have all publicly donned hair shirts to demonstrate their contrition. Dimon and Braunstein even took pay cuts, going from earning many millions to some fewer millions.

JPMorgan argues that Dimon and Braunstein told regulators and the public only what they believed at the time. Dimon and Braunstein made mistakes, but they quickly worked to clean them up, fire those responsible and change their ways. The losses were small relative to the size of the bank and, if anything, demonstrate the strength of JPMorgan's diversified business. After all, the bank made record earnings last year.

But I suspect that if you dosed JPMorgan executives with Pentothal, they would reveal they believed all of this attention was a media creation and political showboating — still a "tempest in a teapot."

"Not true," Evangelisti, the JPMorgan spokesman, said. "We acknowledged from the outset that we made significant mistakes, and we have repeatedly apologized for them. We do not blame the media or regulators for these issues. This was our fault totally. All we can do now is fix the problems and learn from them."

As has happened so often in the wake of the financial crisis, we are left with the spectacle of bankers — here the well-compensated Dimon and Braunstein — insisting that they were clueless and incompetent, which would shield them from any allegations of intent to defraud.

As for many longtime officials at the Office of the Comptroller of the Currency, they may well think that this was merely a nuanced mistake that calls for nothing more than careful suggestions of remedies that don't harm the bank too much. The new head of the agency, Thomas J. Curry, has begun to clean house and re-energize the place, but the overhaul that is needed looks too big for one person.

So let's take a moment to celebrate a handful of American heroes, Sen. Levin and the staff members at the Senate Permanent Subcommittee on Investigations. Because of them, this corruption has come to light. Friday's hearing served to emphasize how lonely Levin's efforts are. Sen. John McCain, Republican of Arizona and the new ranking minority member on the committee, did a yeoman's job of asking a few questions. Sen. Ron Johnson, Republican of Wisconsin, made a few incoherent statements using the au courant phrase "too big to fail," then scuttled out of the hearing. None of the other senators, Democrats and Republicans alike, bothered to show up.

The 78-year-old Levin, peering over those glasses that seem surgically attached to the tip of his nose, soldiered on.

But let's imagine what would happen if this report does what the senator hopes and puts pressure on the regulators to finalize a simplified and loophole-free Volcker Rule, which would prohibit banks from making bets for their own profit using taxpayer-backed money. Why should we have the slightest confidence that big banks could be persuaded to follow it? And why should we feel reassured that, if they didn't, regulators could or would enforce it?

We shouldn't. And we don't.