You are talking out of your behind. A big part of the modern NFL game is extending plays and the scramble drill. Aaron Rodgers has made a career out of it. Teams actually practice what to do and what to look for when a play breaks down. Wide receivers are schooled on how to get open and come back for the ball. These things are planned and worked on.
There are always things to work on from the previous game. Brady, Manning, Brees, etc. will tell you they always have things to look at and work on after a game. That's a given.
Stats are stats. Allen's stats perfectly represent the game he had. No QB is ever 100% completion percentage in a game (Brees got close last year) which means every QB misses throws, or has the passes defended, etc. And every QB throws INT's. So yeah, Allen does have stuff to work on and always will till the day he retires.