Elaugaufein
Member
Conner existed but all memories of him were scrubbed like with Wally. Manhattans way of dealing with people is more like taking them off the table while leaving the game still ongoing.
That explains his memory not changing (sort of, I mean logically his memory should still proceed from the memory erased Tim Drake but *handwave*). But it doesn't explain how he can hurt himself by hurting Tim, since there Timelines had already diverged before he performed the action. Not sure if its an oversight, new rules for time travel in this era, or what happened with Wally / Kadabra / Post-Crisis Clark who initially seem to remember the Post-Crisis universe but fairly quickly get integrated into the N52 timeline with alternate reasons for their memores / experiences being presented.