Horrible Mechanics

[njdevs00cup]

R1 and R2 and one out. I've got the plate. I told my partner during pre-game that I would take the call at third base on a tag up. Batter hits a bloop into center field, which F8 charges and appeared to trap. BU gives no signal and no verbal. Runners don't know whether to return to the base or run. I don't know whether to come up the line to make a call on a possible tag up into 3B. Apparently BU ruled the ball was caught because F8 threw the ball to F3 to double off R1.

The question which popped into my head as I was driving home is what should I have done if the throw went into third base, as this could have been a tag play (assuming R2 went back to tag and the ball was caught) or force play (if the ball wasn't caught)?