Updated: 10:45 a.m. | They may be referring to it as the “Calvert amendment,” but House Democrats and Republicans agree: Whatever prompted Rep. Ken Calvert to come to the floor late Wednesday night to offer an amendment to reverse an earlier vote to ban Confederate flags at federal cemeteries, it wasn’t the California Republican’s idea.

In the hours that followed, culminating in GOP leadership pulling its first appropriations bill of the season, lawmakers said it was unfortunate that Calvert, chairman of the Interior-Environment Appropriations Subcommittee, was getting much of blame for the events that transpired.

“Ken wasn’t defending the amendment,” said Rep. Mike Simpson, R-Idaho, the chairman of the Energy and Water Development Appropriations Subcommittee. “But now … he’s the bad guy, he’s the racist out there, and that’s sad, because that’s not Ken.”

“He’s a gentleman,” said Interior-Environment Appropriations Subcommittee ranking member Betty McCollum, D-Minn. “He runs his committee in a very open, fair, transparent matter. He’s got great, transparent staff, which is why the fact that this happened is a total shock.”

There’s still a lot to learn about who made the decision to send Calvert out to undo the amendment prohibiting the Confederate imagery on certain government grounds, which GOP leaders calculated was necessary to win Republican votes on a measure that was already on life support.

However, members and aides on both sides of the aisle shared versions of events with CQ Roll Call Thursday that suggest the calculation was made at the very top, at the eleventh hour and with little to no coordination or communication with Republican appropriators who would ordinarily have been kept in the loop.

After nearly 20 hours of debate on various amendments to the Interior-Environment spending bill, it looked like members were finally wrapping things up on Wednesday night. Calvert, McCollum and Democratic appropriator Chellie Pingree of Maine were the only lawmakers paying attention to floor proceedings.

“I usually stay around for most of the debate on the Interior bill, but I had to go get my dry cleaning so I’d have something to wear today,” Simpson recalled. “I got home and turned on the TV and Ken was using his motions to strike the last word … and I said, ‘What’s going on?’ And all of a sudden somebody hands him this amendment and he does it and I kind of go, ‘Oh, shit.’”

Back in the chamber, McCollum and Pingree were noticing something strange as well.

“All of a sudden, there was this slow lag,” McCollum said, “and Calvert starts talking about wildfires and climate change and striking the last word,” the latter a parliamentary maneuver to keep talking beyond the time allotted.

The real red flag was the sudden appearance of leadership staff, namely senior aides for Appropriations Chairman Harold Rogers, R-Ky., and Speaker John A. Boehner, R-Ohio.

“We’ve had really good communications between Republican staff and the Democratic staff on the Interior committee, but these were new folks who were kind of coming in,” McCollum went on. “And the next we knew there was this amendment being handed to us as the clerk was reading it.”

“I watched what looked like an unexpected event for Mr. Calvert,” Pingree said. “It didn’t look like this was his idea and it seemed like there was a lot of agitation on the floor.”

The amendment, written on the fly, didn’t mention the “Confederate flag” once. It sought to codify an Obama administration memo stating the Confederate flag may be flown on very specific ceremonial occasions in federal cemeteries, but what it was really doing was reversing California Democrat Jared Huffman’s amendment, which had already been adopted by voice vote, that barred all such practices. It took time for everyone to figure out what the language actually meant.

Appropriations ranking member Nita M. Lowey, D-N.Y., was the first out with a written statement condemning what had just taken place. And Pingree, also a member of the House Democrats’ new messaging group, emailed the group’s chairman, Rep. Steve Israel, D-N.Y., who also sits on the Interior-Environment appropriations subcommittee. Israel, who was home that evening and reading a book at the time, sprang into action, sending emails late into the night and early morning hours.

Meanwhile, Pingree and McCollum ended up at the Democratic Club a stone’s throw from Capitol Hill, where they ran into Huffman and other colleagues and told them the news, to everyone’s disbelief.

With such a politically sensitive situation, it makes sense Republicans wouldn’t have looped in Democratic counterparts. What’s surprising was how disconnected GOP lawmakers were from the process, even those who sit on the Appropriations Committee.

Several aides for House Republican appropriators told CQ Roll Call that at one point during Calvert’s nearly 30-minute floor speech to stall proceedings while staff wrote up the new amendment, they all received an email asking if any of the lawmakers for whom they worked were still in the building. A few minutes later, a second email came through to the effect of “never mind.” People thought it was odd, but didn’t give it too much consideration. Many of them were already asleep or unplugged from their electronic devices, thinking everything had wrapped up drama-free.

Rep. Chris Stewart, R-Utah, a member of the Appropriations Committee, told CQ Roll Call on Thursday morning he’d been out at dinner the night before, with a cellphone that had just enough battery life to call an Uber to get him home. He didn’t find out about the developments until later, even though one of his dinner companions happened to be House Majority Leader Kevin McCarthy.

“I was having dinner with Kevin and some other people,” Stewart said. “I think [colleagues] tried to inform me, but as I said my cellphone wasn’t working.”

Stewart said McCarthy didn’t make mention of what was going on at the Capitol at all during the dinner with some members of the Western Caucus. On Thursday evening, one House Republican, upon hearing this from CQ Roll Call, said it didn’t surprise him: Leadership didn’t anticipate this floor action would have nearly as much consequence as it did.

Republicans were ultimately unprepared Thursday to face the wrath of House Democrats, who seized on the fact the chamber was set to vote on the “Calvert amendment” the very same day — perhaps the very same hour — that South Carolina was taking down its Confederate flag from the state capitol building.

In speech after speech on the House floor, Democrats talked about the shooting at the black church in Charleston that spearheaded the national movement to remove Confederate imagery in public places.

Minority Leader Nancy Pelosi forced two proxy votes on the second privileged resolution in two weeks that would call for the House to take down its display of the Mississippi state flag, which incorporates the Confederate flag into its design.

“A good message is exploiting bad ideas,” Israel told CQ Roll Call with a wide grin.

Around the time Republican leaders announced they would no longer be holding a final passage vote on the Interior-Environment appropriations bill, Calvert sent out a statement.

“The amendment offered last night … was brought to me by Leadership at the request of some southern Members of the Republican Caucus,” he wrote. “To be clear, I wholeheartedly support the Park Service’s prohibitions regarding the Confederate flag and the amendment did nothing to change these prohibitions.”

“Any one of them could have asked for a roll call vote then, and nobody did,” Simpson said of the Republican opponents to whom Calvert referred. “None of them had the balls … they had Calvert do it, he got sucked into it.”

Rep. Raul M. Grijalva, D-Ariz., the ranking member of the Natural Resources Committee, said this about Calvert: “The chairman of that subcommittee has to fall on his sword. … He’s a decent guy — he knew this wasn’t right. And like a soldier he goes out and falls on his sword for the rest of them.”

Lauren Gardner contributed to this report.