NFL rules question from the Patriots Titans game

[dolphins4life]

This involves the punt at the end of the game.

The punt was rolling into the end zone so the Titans player grabbed it.  If the ball had stopped rolling in the field of play, how many seconds pass before it they call the play over.

[fyo]

Rule 9: Scrimmage Kicks
Section 4, Article 4:
BALL OUT OF BOUNDS OR NOT RECOVERED IN FIELD OF PLAY. If a scrimmage kick goes out of bounds
between the goal lines or is lying in the field of play with no player attempting to recover it, it is the receiver’s ball at the dead-ball
spot, unless the special rules for missed field goals in 11-4-2 apply.

Basically, the refs have some leeway in when to blow the whistle, but if no one is making a genuine attempt, they are going to blow it pretty darn quickly.