So you didn't understand cross contamination.
If the transfer of fibers happened while the DPD was handling the evidence they are irrelevant to the case.
What ever case you're trying to make.
I absolutely understand cross contamination.
Finally, you decided to make a point, regarding such a thing.
Show your evidence that the jacket was sitting beside the arrest shirt on a table top or that the two were placed in a box together or anything like that. Go on. I'll wait.