Is this a foul?

[dumbref]

First - I agree with the call. It certainly falls under player safety.

With that said, it is difficult to tell from your description exactly where the foul occurred. Your WH may have been more concerned with the area of the field you were observing than the call itself. When the ball carrier enters the opposite sidezone, you should turn your attention to an area behind the U & BJ (5 man). We should have at least 3 sets of eyes (L, BJ & U) watching that sidezone. Our weak area is now in the middle and deep. You should not see fouls in the opposite sidezone if you are working your area properly.