I love the show, but this episode was beyond ridiculous. I can accept that they had to do some ret-conning in order to bring that particular affair to a close. But there was no need for the many many conjectures they made to be so extremely far-fetched. Not even a psychic could have come up with this stuff. A lot of very lazy writing must have gone into this - plus a need to rush things (perhaps certain recurring characters' contracts were up and they did not want to renew them beyond season 6??). All this conjecture was made worse by them cramming a lot of plot development into 40 minutes. There was more than enough plot here to do a two-parter that would have been decently paced and would have given the plot and the twists and "discoveries" the necessary room to breathe. Yet, they choose not to do this as a two-parter. Perhaps they did not have the time because they were getting too close to the end of the season??
