I'll post this too now that im on my computer
A.R. 15.104 Heel/toe
Third-and-10 on A30. A2 controls a pass and gets his left foot down in bounds at the 50. As his right foot comes down, the heel hits in bounds and in the normal motion of taking a step, his toes hit out of bounds. Officials rule complete.
Ruling: Reviewable. A’s ball fourth-and-10 on A30. Incomplete. Adjust clock if wound before review. If any part of the foot hits out of bounds during the normal process of taking a step (no drag or delay), then the foot is out of bounds.