wonder if they were not aware that it was possible or whether they were lying. I’m not sure which one is worse.

They knew it was possible,.although it obviously wasn’t intentional.

The only way this can happen is if they hold copies of the keys used to encrypt/protrect your traffic, and can give them to anyone at any time. Or if there’s no keys at all, and someone simply needs an ID to pull the right stream. Something like your password isn’t required to make the key useful (or they’re storing/using it in a reversible way). And anyone that compromises them can access whatever they want.

Unfortunately I dont know if anyone that does “cloud” camera stuff, including Reolink (and pretty much all of the other consumer camera makers) are any better here. I’m not sure that they’re as bad, but I bet most are. Clearly providers like Ring are.