Earlier quoted context omitted.
I don’t know anything about the specific case, but often DNA from someone else would be totally irrelevant. If I murder someone with my kitchen knife, my wife and her fathers DNA will be on the murder weapon. If you buy a gun from someone and then go shoot someone with it, it might have the sellers DNA on it. So it’s sometimes the case that DNA can’t really create reasonable doubt.
Not just the seller, workers at the manufacturing plant, and any person who walked in the shop and asked to hold it.
What they'd actually identified was the factory worker who packaged the DNA collection swabs.