R1 slides through B2’s legs – Interference?

[Angler]

NFHS – very low-level girl’s Varsity

R1 on 3B. Ball pitched to the backstop. R1 goes half way, stops. F2 throws ball to F1. R1 runs towards home. No problems with LBR, but B2 is standing in the box waiting for her next pitch and F2 is crouched in her position, when R1 slides between the legs of B2 to reach home. As this happens, F1, who hasn’t yet taken her position on the rubber, throws to F2 to try to retire R1. F2 just stands up to catch the ball and then watches R1 slide into home through the legs of B2. No contact anywhere. No attempt by the catcher to make a play.

PU did not call interference. Talking with him after the game he said he couldn’t call interference because “neither the batter nor the catcher were aware of the play.” I know most interference is a HTBT sit, but do you agree with a no interference call?