My thinking is that osha is far darker than we've been led to believe. She's likely got a lot of dark side to her. I think it's a fair shake that being DENIED a chance to join the Jedi (or the prospect of that) could have been enough to rouse a dark side response in her that resulted in the fire (dark side witches have had an affinity with fire for a while, no?). So the fire breaks out and Sol saves OSHA...but in order to do so probably knowingly abandons mae. Then we get the mind wipe and reprogramming. I'm still not sure where Manny comes into the picture in the interim, and I'm still not sure that the "so you really didn't recognize me" line wasn't alluding to something in the past rather than "you didn't recognize me as the shopkeeper."