To me, most "controversial" means which decision generated the greatest amount "controversy", i.e., debate/discussion/argument, etc. That would be the Stras shutdown, which of course has already been talked about way more than the other cjoices. I think what we're really voting on is what we think was the WORST decision.
To me, it's the managing of the 7th inning last night. Barrett rather than Clip is one of those mistakes, as was not getting Bear out of the sooner when it was clear he was off. But the biggest one, the one that is completely inexcusable to me, was letting Thornton face Posey. Horrendous decision/reaction to a completely foreseeable situation.