I think this is completely plausible. The question I had is, why is he there with the team if he already told the FO he's quitting? They got busted trying to withhold it from the fans.
No head coach would let a player who just quit be mingling with ex teammates during a game without a reason.
Obviously not similar in terms of what the player did for the organization but if Vontae Davis came back out in Bills attire and it broke he quit ......
They weren't booing because they don't appreciate what Luck meant - they boo'd because he shouldn't be out there.