Basketball ref with a question

[fullor30]

Ok, I jumped over from the b-ball forum with a baseball question from my son's game yesterday.

Man on third, two outs, 3-2 count, runner going, strike three, dropped third strike. Batter gets out of way of runner who slides 'safely' home, batter rather than running to first , starts to walk back to dugout. Ump calls batter out for doing so, then indicates that run scored before he signaled out.

I say impossible but can't give rule( our team was given the run). Umps a friend of mine and he couldn't site the rule and both he and partner thought it was correct call. I know that once you head for dugout, it's an out, but would bet a cold one that run doesn't count.

Thanks........