statutes that protect […] people trying to cooperate with law enforcement,

I don’t know exactly about France, but such a concept is rare in Europe in general (except England), and even more so when it comes to possession of such materials.

In Germany, I know the tolerance is absolutely ZERO, and the excuses too. You can carry the material to the police to deliver it, and with that you have proven that you were in possession one second before (it is very different with illegal weapons btw.). Private investigators or journalists have tried to do reports about the topic, seriously and neutrally without any doubt, but got punished for possession then.

That doesn’t count for this kind of crime.

It’s not even certain whether or not it applies at all for fediverse systems.

Better delete it in the same minute when you found it.

Probably should have given all of the evidence to the police instead of deleting some of it.

Or maybe not. …

In most western jurisdictions platform operators are not liable for user content

Around here, OP would then automatically be a suspect for possession of the material. Possession is a crime. And that is far from funny. Better have a very good lawyer from minute 1.

Is this different than pihole?