Water resistant means some resistance to water. Water proof means full resistance to water. And that is a standard term that has been in use for decades to describe watches, tents, jackets, etc. When I read tamper resistant, I imagine the tamper equivalent of water resistant.

Tamper evident is the correct description of what the parent comment is talking about. You can Google “tamper evident stickers” to see it’s how the phrase is widely used. I would say the epoxy in question is both tamper resistant and evident though. Because it’s both difficult to remove and you’d risk breaking the device if you tried it, and those seem like obvious tamper resistance controls to me.