Situation:
Bases loaded, no outs. Batter hits grounder to 2B (4)who throws to SS at second base. Throw to 1B is wide and gets by 1B. BU rules interference on R1 sliding into second. Batter ruled out at first. BU brings R2 and R3 back to original bases after both scored on overthrow. Is that the correct ruling? His reasoning was the ball was dead at 2B on the interference.

The call was correct.

Don't know about the call. HTBT. But the ruling was sound.

That's what I meant to say. Thanks Jimmy.

Call was correct too, spoke to my player afterward and he slid into to 2B short of bag due to wet conditions and popped up just as the SS released the ball, forcing a wild throw. Nothing malicious but correct call and ruling.
My only question now is, what is the reasoning of bringing the runners back since interference or not, R3 scores due to force play. It seems overly penal to the offensive team.

It is a very punitive ruling. The FPSR(force play slide rule) is a combination interference call and a safety rule.
An ordinary interference is going to bring the runners back also but doesn't create an automatic double play.

You can get the same ruling under pro rules if you judge the interference to be intentional.