A good lawyer can bring this up; that there is no chain of custody .. but you need to afford a lawyer. If someone in a low paid job is incentivised to find this evidence, they could occasionally just plant it, get their few extra $$ a few times a year, and some other low paid worker could get screwed over because they can't afford anything other than a public defender.

They then get a sex offense charge, can't get a job, are looked down upon by all their friends/family no matter how much they claim innocence and get even poorer.

I realize a Geek Squad member isn't quite as low income as you can go, but it's still low income people incentivied to hurt other low income people. .. Mortys killing mortys.