Matt Murphy gives another explanation for Patrick's DNA being found in the Lindsay Clancy trial

What about the fact that her DNA is not on the bands but his is? Okay, another thing. There are people that are called shedders. Some people, Billy, for reasons that we still don't know scientifically, shed DNA. They'll have DNA on everything they touch. They will have DNA when they breathe. There's different ways that DNA can be shed. Sometimes it's skin cells. Patrick is a shedder. Patrick's almost certainly a shedder. She just might not be. I had a murder case where I had two guys, a guy murdered his girlfriend, brutal stabbing, and he was with his cousin. The cousin was there for about 30 seconds. The cousin touched the car, and the cousin touched the jeans of my victim as he helped load her into the trunk. Cousin's DNA was on everything. The boyfriend had been driving around in the car. DNA was on nothing. We did not find his DNA, and we expected it to be there because he was with her. It should have been there. He just wasn't a shedder. DNA, again, can be wonderful, but it doesn't apply equally when you're talking about transfer of DNA to objects. Every forensic scientist in America has heard that argument and rolled their eyes. That shuts down about a quarter of the internet.