I swear there are 15 different rules on what constitutes going out of bounds and where a ball is spotted. For example:
1) Today Lamar extends the ball before stepping out of bounds. Where he lands out of bounds is well past the line of gain. But he's deemed short because (I'm guessing here) the ball broke the plane of the sideline behind the line of gain?
However...
2) A wide receiver is considered catching a ball inbounds as long as two feet are inbounds, even if the ball is obviously thrown out of bounds.
3) Someone can score a TD, even if the ball is held out of bounds outside the pylon, as long as they cross goal line extended.
The NFL can't even agree what inbounds and out of bounds are.