Corrected entry: When Frank is looking at the picture of his daughter he rips one big piece, but when the camera pulls away you see him drop one piece then rip another piece and let them fall. Back zoomed in, only the one big piece is missing.
Corrected entry: When explaining about the car, 'Coach' points at the twin guns on the cars hood saying "and twin 30mm, belt-fed machine guns for offense". Looking at the guns one can easily say that those are not 30mm guns. Such guns are mounted on anti-tank aircraft and measure few meters in length, plus of course have much wider barrels. the guns on the car are at best 30 caliber ones, which is 7.62mm.
Corrected entry: It's established that whenever Machine Gun Joe kills another racer, he cuts his face in the "tick mark" style - four vertical marks followed by a horizontal one (as his scars show.) After killing Grimm "Reaper," he is shown making a horizontal mark, but the leaderboard in subsequent races shows his kill count as something that's not a multiple of five (and he didn't score any more kills in the meantime, remember).