User blog comment:DCFreak22/Miss Martian's Grey Area - Justice League Oblivious?/@comment-96.241.72.70-20120616213054

To back theory number 2: J'onn did state in season 1 that while M'gann was untrained, her psychic potential was possibly great than his. If she managed to effect his mind in Failsafe and make him forget it was just a training exercise along with everyone else, she could probably make him forget he noticed what she did to that Krolotean.

I'm very much hoping that M'gann and Connor do get back together. I'd rather the series wrtiers didn't bother to make us attached to a couple (Terrors and Bereft are two of my favorite epiosdes and made me a fan of the couple), make a running sub-plot of the breakup and the reasons behind it for there not to be some closure. One possibility is that when M'gann finally pulls heself together and realizes what she's done, she decides to take a break from the team between season 2 and 3. (It happened in the comics, which makes me think it might just happen.)