Tyrann Mathieu's personal foul on the 2 pt conversion

I took another look.

Mathieu was running full speed. Baker throws the ball, Mathieu's back foot from the previous step lands, and he takes one step forward into Mayfield.

I suppose it can be debated whether the back foot landing is considered a step (I don't think it was, I still say he took one step) but there is no way he took more than two.
  1. When the passer goes outside the pocket area and either continues moving with the ball (without attempting to advance the ball as a runner) or throws while on the run, he loses the protection of the one-step rule provided for in (a) above, and the protection against a low hit provided for in (e) above, but he remains covered by all the other special protections afforded to a passer in the pocket (b, c, d, and f), as well as the regular unnecessary roughness rules applicable to all player positions. If the passer stops behind the line and clearly establishes a passing posture, he will then be covered by all of the special protections for passers.