I agree with you in that he's the most logical choice for the murderer, but in this country, fortunately, the defendant need not suggest an alternative theory when the prosecution fails to meet his burden.
I know, it's just a shame. Besides gypsy thieves and serial killers who target pregnant women with dogs, I just don't see who would have done this (sarcasm). I feel for her family having to find out he was having multiple affairs and that their daughter's life was not what it seemed to be. Sadly, there are plenty of women out there who would still be attracted to him after all this.