Someone might of just claimed to be you. The security at banks is .. no existant for saftey deposit boxes they don't give a damn.
The security of safe deposit boxes is a lot more than non existent; banks stake their reputations on providing that security.
You generally need to prove who you are (ie that you are authorized to even enter the room with the deposit boxes) and have a key to gain entrance to your box; if you lose the key, the bank doesn't just have another to provide you - they need to drill out the lock. They're pretty rigid on that. If you're not the box holder, then you better be the named executor or trustee of the person whose box it was.
For that reason I disbelieve that authorities would be interested in OPs small amount of Bitcoin, and if they were, it would be readily apparent that they'ed been there, as your lock would either be drilled out or yourbkey wouldn't work.
The part about drilling out the lock is recited every time a person rents a safe deposit box but it is silly. Safe deposit locks are far simpler than auto ignition locks and can be picked in a few seconds by an amateur. The security is in the fact that amateurs do not have easy access to the vault.
There is no doubt that some one was in the safe deposit box between the time I closed it and the next time I accessed it. There is no doubt. I'm emphasizing that. There is no doubt.
One hard drive that was stored there worked fine when I put it there. When I retrieved it, it no longer worked. It is possibly a coincidence. Maybe it broke from some other cause. But it is unlikely.
Of course law enforcers making 100k plus per year do not steal small amounts of altcoin to supplement their income. No argument there.
But in the United States, harassing and intimidating people who don't show respect for 'law enforcers' is the norm now. At every level, but most notably at the federal level, that has become the signature of 'law enforcement'.