Bipartisanship was busting out all over Capitol Hill on Thursday — and not just on the outlines of a Wall Street bailout. More than a year after a House floor blowup that had Republicans charging Democrats with abusing their power to steal a vote, a bipartisan panel established to investigate the incident unanimously agreed to a single version of the event and recommendations aimed at avoiding a repeat.

The yearlong, $500,000 investigation stopped short of a rebuke of House Democratic leaders — which Republicans on the committee had sought originally — for their conduct on the night Aug. 2, 2007.

It found, however, that Democrats had presided over an illegitimate vote tally. And it recommended lawmakers drop from House rules a prohibition against holding votes open for the “sole purpose” of reversing their outcome. Democrats made that change last year in response to the more than two-hour vote that Republicans held in 2003 to muscle through their prescription drug bill. But the report said the rule had proved unworkable and only added to the confusion on the night of the incident.

That night, the House erupted in chaos over the disputed results of a vote on a Republican-authored measure to prevent illegal immigrants from accessing some federally funded benefits.

Republicans argued that the presiding officer, Democratic Rep. Mike McNulty (N.Y.) — under pressure from Majority Leader Steny Hoyer (Md.) — prematurely announced a 214-214 tie vote, therefore defeating the proposal, when the final tally showed it should have passed, 215-213. Testifying before the panel, Hoyer acknowledged telling McNulty to close the vote, but the report noted that McNulty said he did not hear Hoyer and felt no pressure to gavel the vote closed early.

The report backed up the Republican contention that the final vote was wrong but did not say whether the GOP should have won or lost it. The report was circumspect in assigning blame, calling the incident the result of “the perfect storm: a long and contentious week; a close vote on a politically sensitive issue; the lateness of the hour; urging from the Majority Leader and other Members to close the vote;” an attempt by McNulty to abide by the new House rule limiting extended votes; and a breakdown of the chamber’s electronic voting system.

McNulty, who is retiring this year, also took some lumps. “Out of concern and confusion, he failed to follow the long-established procedures for closing a vote, unintentionally leading the House into uncharted territory, and thereby raising concerns about the legitimacy of the vote,” the report said.

Rep. Bill Delahunt (D-Mass.), who chaired the select panel investigating the incident, chalked up the confusion that night in part to the fact that Democrats, eight months into their majority, were still unsteady at the levers of power. Likewise, he said Republicans continued to struggle with adjusting to life in the minority. Delahunt said, that since then, “the operation of the floor — I’m not saying as a direct consequence of Aug. 2 — is much more efficient. I’ve noticed a better atmosphere on the floor.”

About an hour after Delahunt made those remarks to reporters Thursday, events on the floor provided a fresh reminder that a late-session crush of legislative action can still set off partisan fireworks.

Democratic leaders had to cancel a vote on a tax-extenders package and send the bill back to the Rules Committee after a mix-up caused that panel to approve a rule for a bill $100 million more expensive than the entire House later approved. Rules ranking member David Dreier (R-Calif.) criticized Democratic leaders for trying to cram through too many bills at the end of the session. “Moving rapidly like this does create the potential for problems,” he said on the floor.

The report’s recommended rules change — and its proposals for streamlining the voting process — won’t be addressed until next year, if at all. Speaker Nancy Pelosi (D-Calif.) thanked panel members “for their balanced and thorough bipartisan review. We will take their recommendations into consideration for the 111th Congress,” Pelosi spokesman Nadeam Elshami said.

While panel members went out of their way Thursday to praise the bipartisan effort behind the report, Republican leaders framed the result of the investigation as an indictment of House Democrats. “Sadly, this is yet another black eye for the Democratic Majority of the House and their management of this institution, which has been anything but open and honest,” Dreier said in a statement.

Similarly, Minority Leader John Boehner (R-Ohio) in a statement called the findings “another black eye for this Democrat-led Congress.” He said the report “shines an even brighter spotlight on the lack of real leadership in the House of Representatives.”

Jen Bendery contributed to this report.