It is absolutely interference, I think they screwed up the call a couple other ways. This appears to be UT HS softball, I have no idea what their rules say. I am making this ruling based on both USA and USSSA Slow Pitch rules, it is entirely possible that FP rules are different, but I don't think so.
I have interference on the B-R. That call is entirely judgement by the umpire. It is the responsibility of every offensive player and coach to not interfere with a fielder attempting to field a batted ball. There is no requirement for the runner to be in the running lane unless there is a throw coming. My call would be everything stops right there, runners return to bases held at the time of the pitch, we have two outs.
If you do not call interference, the B-R would still be out on the IFF as soon as the ball touches the ground after being touched by the fielder over fair territory. The only ways you would be able to call out R3, is if the B-R interfered after being called out, the interference was an "obvious attempt to prevent a double play," or R3 somehow interfered. The biggest problem I have is if they are calling interference, the play is DRT, and the runner who interfered is out.