[Andy]

My opinion.....

In the scenario posted, the batter is awarded first base due to the HBP, the runner on third is forced to home as the bases are loaded.

Once a runner passes a base, s/he is considered to have touched that base for purposes of an appeal. My thought would be that if s/he did not show any inclination to turn around and touch the plate that was missed, s/he has (in his/her mind) completed the base running duties and is subject to appeal.

If it is clear to me that the runner did not react until the coach yelled at the catcher, then I would definitely consider the runner to have completed the base running duties. In NFHS play, the statement from the coach would be a valid dead ball appeal. In ASA play, it would not be a valid appeal, but once the catcher made a move to tag the runner, I would consider that a valid appeal as I would know what the catcher's intent was because of the instructions from the coach.