It would be a situation like this where it might be helpful for you, through discussion with him, to have access to his Google account. If the password can be reset, maybe be involved in that reset process and make it a password you then make note of. A password manager for him might also be useful. My dad (77 this year) has one, and I know the master password for it so if something were to happen to him I can get to all his accounts to take the action needed. The password manager we use (I have the same one with my own account) also has a way to designate someone for emergency access.
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