His access to the account was not legally terminated - it is still his account, it is active, and it's okay to use that account - if he had other linked cameras, that would be the point to use them.
However, the issue is that his account shows data also from a device that isn't his (anymore). He has access to the cloud service, but simply the set of valid devices should be empty, and isn't.
However, the issue is that his account shows data also from a device that isn't his (anymore). He has access to the cloud service, but simply the set of valid devices should be empty, and isn't.