Bengals coach Marvin Lewis said Wednesday during a news conference he doesn't know if he's "ever really heard of" a trade being derailed because paperwork wasn't filed on time.
"All you have to do is notify the league office you're making a deal, and that's an easy thing," Lewis said. "We spoke to a person in (the league office) that (said) our (paperwork was) there."
The Bengals reportedly would have received a second-round selection and a third-round pick in next year's draft for McCarron, who played for Browns coach Hue Jackson when he was Cincinnati's offensive coordinator from 2014-15 and is 2-2 as an NFL starter, including 0-1 in the playoffs.
"It's not a good situation," Lewis said. "AJ's a very valuable member of this team, and I told him that yesterday afterward. Frankly, I was relieved (we didn't trade him). He's a great kid. He's a true team player. He's a leader on this football team, and that's why we felt like he's such a valuable asset."
A league source said the deal came together close to the deadline, and while scrambling, the Browns emailed a signed trade agreement to the Bengals under the impression Cincinnati would sign the same document and send it to the league office. However, the Browns did not send the agreement to the NFL.
The Bengals sent a trade agreement in time to the NFL and copied the Browns on the email, but the document only had a signature from Cincinnati on it, the source said.
The NFL confirmed it received paperwork from the Bengals before the deadline but did not hear from the Browns until after 4 p.m., another league source said. Both teams are required to notify the NFL in writing of a trade prior to the deadline for it to be approved.
The Browns pleaded with the NFL to allow the trade, but the league rejected the request, a source said.
Jackson's interest in McCarron and fellow quarterback Jimmy Garoppolo, whom the New England Patriots traded Monday to the San Francisco 49ers for a 2018 second-round pick, has been well known in league circles since early in the offseason. But a disconnect between the Browns' coaching staff and player personnel department regarding the value of McCarron hindered trade talks dating to the spring, the Cincinnati Enquirer reported.
All of this has given rise to speculation about whether someone in the front office deliberately sabotaged the trade, which would represent a new level of dysfunction, even for the Browns.
Either way, the dragging of feet as it pertains to the trade ultimately backfired on the Browns, who have started 28 quarterbacks since 1999 and are 1-23 under the regime led by Brown, Jackson and chief strategy officer Paul DePodesta.
As for McCarron, he told reporters Wednesday in Cincinnati his agent called him at about 3:30 p.m. Tuesday and said he thought the 2014 fifth-round draft pick from the University of Alabama would be traded to the Browns. Shortly thereafter, McCarron saw reports on Twitter about the trade falling through. McCarron said he and his family were getting ready to host Halloween festivities at their home when everything happened.
"I'm not angry about anything, not upset," said McCarron, who's spent his four NFL seasons as Andy Dalton's backup. "It feels good to be wanted by the team you're on, by another team.
"I talked to Marvin (Lewis) for a little bit yesterday, and he told me he was still glad to have me here. Today I'm going to thank (owner Mike) Brown personally just because I admire he was going to give me the opportunity to go start and play somewhere."
Garoppolo, a 2014 second-round pick from Eastern Illinois who'll turn 26 Thursday, is scheduled to become an unrestricted free agent in March. McCarron's status isn't as clear, though. The Bengals are waiting for an arbitrator to rule on whether McCarron, 27, is set to be an unrestricted or restricted free agent next year.
McCarron explained he was enthusiastic when he first heard about the trade because "I'm a big competitor and you want to play and you want your opportunity."
He looked forward to reuniting with Jackson, only to be told never mind.
"It would have been really exciting," McCarron said. "But it didn't happen."