Scrimmage Kick/Momentum

[Jaysef]

During JV game last night, a punt rolled to the 3yl, where R picked it up, and his momentum took him into the EZ. Our BJ immediately blew play dead, and signalled a TB. I felt something was wrong with this, but kept it for post game discussion, since no coaches went ape over this. We spotted it at the 20yl and game continued.

In the interest of judicious officiating, should I have made sure the ball was spotted at the R's 3yl (momentum?), since play stopped, and the ball did technically become dead in R's EZ?

OR, was my BJ correct, since 8.5.3.a.1. ...any free kick, or scrimmage kick, which is not a scoring attempt...breaks the plane of Rs goal line...is a touchback.

Confused Umpire