4 or 5 years ago; I was slow with the whistle, allowing the ball carrier to fight for yardage even though there was a defender on his back.
The resulting gruesome broken leg injury I witnessed sure made me wish I had blown the play dead early.
Page FR-98 of NCAA Rule Book has the following under Rule 9.4:
Note 2: Defenseless player (Rule 2-27-14). When in question, a player isdefenseless. Examples of defenseless players include but are not limited to:
And then . . .
• A ball carrier already in the grasp of an opponent and whose...