Dead ball passing runners, runs scoring

[mikebran]

Play: Bases loaded, 2 outs. Batter hits over the fence HR. R3 jogs, R1 admires hit, and hard running BR touches and rounds 1st and passes R1 between 1st and 2nd. AT THE TIME of the passing R3 has not reached home.

Is this a time play? "That's passing, that runner is OUT!" and the 3rd out and no runs score? Since R3 has not touched.

Or is there a rule reason to score runs? How many?