On a fourth-and-3 in the third quarter of Sunday night's game, all but two Colts players lined up on the right side of the field, almost completely outside the numbers and two yards off the line of scrimmage.
The attempt to confuse the Patriots, and perhaps try to draw them offsides, failed.
Instead, Griff Whalen, who was essentially lined up at center, snapped the ball to Colt Anderson, who was swallowed up by Brandon Bolden, giving the Patriots the ball back.
A flag was thrown for an illegal formation.
"The whole right side of the line was not on the line of scrimmage," the official said.
"That was insane," NBC commentator Cris Collinsworth said.
Colts coach Chuck Pagano took responsibility for the botched play.
"I didn't do a good enough job of coaching it during the week," he said. "Alignment-wise, we weren't lined up correctly and then a communication breakdown between the quarterback and the snapper and that's all on me."
Coach Bill Belichick said the Patriots were expecting the Colts to run some type of trick play.
"We expected this to be a gadget game in the kicking game, the onside kick, some kind of fake — fake punt, fake field goal. The punter ran a sweep against Tennessee a couple weeks ago. That's something they've done in the past.
"We didn't know what the play was going to be obviously, but they went on the swing-gate type play. We went over to the overshift and made sure we covered the inside part, reacted well to it. It was a good heads-up play by our punt return unit. Thought we had good coverage from those guys from the opening kickoff."
Patriots defensive end Chandler Jones, watching from the sideline, said he thought the formation was peculiar.
"I saw the formation they came out in and I wasn't sure what was going on," said Jones, who had 3 sacks in New England's 34-27 win over Indianapolis. "Great awareness by our special teams."
It was quickly called the dumbest play of all time, turning up some confused and funny results on Twitter.
Pete Carroll off the hook for a few hours. We now have a call almost as bad as the slant pass on second and one from the one. Idiots.— Dan Shaughnessy (@Dan_Shaughnessy) October 19, 2015
Chuck Pagano just rolled out the red carpet for Nick Saban with a bizarre, poorly-executed, illegal fake punt play.— Christopher Gasper (@cgasper) October 19, 2015
It was supposed to be the Patriots embarrassing the Colts. Instead it was the Colts embarrassing themselves with that non-punt fiasco.— MarkMaske (@MarkMaske) October 19, 2015
I'm sorry I just don't know how tomorrow is spent discussing anything other than the Colts' "fake punt."— Michael Hurley (@michaelFhurley) October 19, 2015
Pagano was in good shape; the Colts weren't getting embarrassed and still had a chance to win. And then he does that.— ProFootballTalk (@ProFootballTalk) October 19, 2015
Colts defense had actually done a decent job keeping this game close before it got hosed by that bizarre playcall.— Albert Breer (@AlbertBreer) October 19, 2015
Follow Rachel G. Bowers on Twitter @RachelGBowers.