Why was he doing this again? He could of sworn he said the last time was the last time. He distinctly remembered saying last time was the last time. He got out off the cauldron. No tripping - good sign. He got dressed. No slipping - good sign. He remembered the door killed him the last time, so he waited for it too open. And he waited, and he waited, and the door didn't open. Assuming it was safe Voldemort went to open the doors when they slammed open and smacked him into the wall again.
Lord Voldie died again.