If Allen slides there is what, 2:20 left? KC calls a TO. Bills run into the line, 2nd down KC calls their last TO with 2:10 left. Bills run into the line, 3rd down, 2 minute warning. After the 2 minute warning, Bills run but don't make the 1st down so now it's 4th down. Bills call TO with 1:16 left. Bills kick FG leaving about 1:13 on the clock. Mahomes gets ball back with no TO's needing a TD and only 1:13 left.
Are you feeling confident we win? The odds of Mahomes scoring the game winning TD under these circumstances is much better then the Chiefs going down and scoring and then recovering an onside kick and scoring again which is what they needed after Allen's game sealing TD run.