Allen noted that every possession matters. He said his fumble early in the fourth quarter cost the Bills three points, which was ultimately the difference in the game.
Allen completed 24 of 46 passes for 264 yards, ran for 92 yards on nine carries and caught a 16-yard touchdown pass on the game's opening drive. His fumble was costly, but he did enough to put Buffalo in position to tie the score in the game's waning seconds.
Still, as the quarterback and captain of his team, Allen said he took the loss personally.
"Every loss is personal, and if I can go out there and execute differently -- hindsight is 20/20, but there's some things we should have hit on," said Allen, who is in his second season. "I put that on my shoulders, especially with how well our defense played today. Teams go how their quarterbacks usually go, and I've got to be better for this team."
Their season freshly halted, Allen's teammates sat at their lockers in a stunned silence.
After building a 16-0 lead, Buffalo watched the Texans score 19 consecutive points before Stephen Hauschka's field goal tied the score with five seconds remaining in regulation. But Ka'imi Fairbairn's 28-yard field goal in overtime brought the Bills' feel-good season to an abrupt end.
"It's hard. It's frustrating. We didn't do enough to get it done," Buffalo receiver Cole Beasley said. "Our feeling was it was our game to win. It didn't work out that way."
Experiencing a season-ending loss is something the Bills are familiar with. They have not won a playoff game since 1995, a streak that will continue until at least the 2020 season.
Even after a game they seemed comfortably in control of, Bills players insisted losses hurt the same, no matter the magnitude.
"I'm yet to win a Super Bowl," safety Micah Hyde said. "Each and every loss that I've had -- whether it's the playoffs or, last year, not making it to the playoffs -- it's the same thing. It doesn't matter if you lose by one or lose by 20, a loss is a loss
"The way you go out stings at first, but at the end of the day, you realize that no matter what, losing and not winning a championship is really daunting itself."
Bills coach Sean McDermott, who is one of three coaches in franchise history to make the playoffs twice in his first three seasons, knew there was nothing he could say to "take the pain away" in a locker room that was feeling plenty of it.
Even after he reminded his team how proud he was of its fight, players were still left with a feeling of disbelief.
"He was trying to just be compassionate with us. He knows it's a sucky feeling," guard Jon Feliciano said. "It really sucks. Honestly, I don't think anyone thought we would be going home right now. I love this team. I love Coach, [general manager Brandon] Beane, and I am just so happy to just be here.
"Honestly I just can't believe we are going home."
Home is where the Bills will prepare for an offseason in which they'll have roughly $90 million in salary-cap space. It's also where they'll make decisions on several impending free agents, including starting defensive tackle Jordan Phillips, defensive end Shaq Lawson and guard Quinton Spain.
Phillips made his stance known after a season in which he recorded a team-high 9.5 sacks.
"I hope this isn't my last game with the Bills," he said. "I love the Bills. I hope they bring me back. But it's up to them now.
"We are a young team. We are young. We like to have a lot of fun while we are out there. We don't get this group of guys together very often, so when you do, you have to make the most of it. If we can bring this team back, this won't happen again."
But the stench from this loss won't soon disappear. Whether the Bills learn from it or dwell on it is up to them.
"It's gonna haunt us for sure in the offseason," cornerback Tre'Davious White said. "We'll be back, and it's just gonna make us stronger going forward."