Prigozhin has to know he’s a dead man if Putin gets his hands on him. He must feel protected, and has a plan for what to do afterwards. It’s hard to see what, because his brutality has made it impossible for the west to welcome him, but he seems to have burned his bridges in Russia. Strange indeed.
Maybe he’s just really, really mad and doesn’t care. Maybe he thinks Putin is going to keep him and his men fighting until they are all dead, and he wants to hurt the bastard as much as he can from where he is.