Posters can change their minds dotty but I think you will still keep the count in your stats (ie it won't go back down by 1). Bit of a snub though isn't it!
there's no red writing in my posts and so that means i can't, i'm not bothred now, if my answer wasn't good enough it doesn;t matter but the answer that replaced it wasn;t really an answer lol
I think it's right that OPs should be able to change their choice of best answer as better answers come along. If it was 'once and for all' decision they may never select one just in case a better one comes along. It also makes sense for best answer counts to go up and down as best answers are awarded/replaced. I think the count is only an indicator though- I'm not sure there's much difference between 334 and 335 best answers is there?