Not one thing cost the game. A bunch of things did.
The offsides penalty on the punt, and then they go down the field and score the TD.
That strange call that took away the Bears turnover.
The 1st and goal disaster of a sequence.
The OL being among the worst in the league.
The OC calling plays as if he was coaching a team in Nowheresville.
The personnel put in that disadvantaged the team.
The D not being able to stop them on the last possession of the game.
Caleb throwing 2 picks (1 of them a very bad one).
And yes, Kmet and Lewis blowing that block leading to the strip sack.
All played a part. That missed block was one play. We had to watch the shitshow OC and OL , for example, all game.
Picking which one was THE cause of the loss is dumb, imo.