I confess your choice of words is interesting to me, mon cher. You have always been extremely vocal in your belief that the past life is a past life, and it is and was you. Your belief has always been strong that these are not dreams, but more windows on the past. And yet you're able to say that it wasn't 'you' who made these mistakes. Those two statements seem to be at odds, mon ami.
My advice, such as it is? Unite the two. Either accept that it was you who treated this friend in such a way, or accept that these are but dreams. Only when this logical fault is healed do I think you will find peace on this matter.