I would have expected his job have guardrails in place to prevent this sort of mishap, like a full audit log and chain of custody of all evidence gathered during these investigations, as well as SOPs on the handling and storage of such evidence.
My shared connection to the Realtor dope I wrote about originally is someone I'm quite close to, and through them I've learned some pretty alarming realities of law enforcement.
It seems like the higher up the chain you look, the more indifference or incompetence you find.
Well, let's say, you have a really competent investigator. Is that the person you want to be promoted into a position where they are not doing any investigating anymore? In that light it's good to have the incompetent higher up so that the people doing the real work are those that are competent. :)