Does anyone body else watch Secrets of Forensic Science on TLC?

'Cause I totally do not understand the second half of tonight’s (8901) episode.
Two friends, Rob and Mike Smith, are both suspects in the muder of this couple, but, obviously, they both blame each other and their stories are completely different. Part of Mike Smith’s story is that he met the woman victim at a bar earlier in the night, and invited him back to her boat to have (consensual) sex with him. Rob’s story has no mention of sex.
The medical examiner does a vaginal swab of the female victim and discovers the presense of Mike Smith’s semen. Also, the shirt that Mike was wearing the night of the murder has both his DNA and the woman’s. He is immediatly arrested for the murders.
What the hell? Doesn’t this, in fact, colloborate his story and make Rob appear to be the murderer? There was no mention, by the ME, of the woman having signs of being raped, just that she had sex with Mike Smith.
Could someone (who saw the show, or has a knowledge of this kind of thing) please explain this to me?

Okay, that one sentence is supposed to read “She invited him back to her boat.”

Also, this probably took place in Canada, if that helps any.

They reran the story this weekend. There were a number of reasons they convicted him.

  1. The woman was much older than the two dirtbags, a professional woman, and in a committed relationship with the guy on the boat. It was considered extremely unlikely that she’d have met Mike in a bar and had consensual sex with him. That left rape.

  2. There was some additional evidence, largely that Mike talked to other inmates in prison.

Given that Mike later murdered a fellow inmate and had a burning boat tatooed on his body, it seems like there’s little doubt that they got the right guy.