Stealing in ASA slow pitch (men)

[dsimp8]

The runner on first will attempt to steal 2nd. Two questions 1) If the runner leaves the base before it crosses Home plate, do you kill the play immeadiatly or do a delayed dead ball? 2) Who has the call on if the runner left early PU or BU? To me the PU can tell if the ball crosses the plate which the BU may not be able to see effectivly but the PU can't have his eyes in two places watching the pitch and the runner. I am assuming it is the BU's call.