@hanung665 You'd have to get out-of-band verification, or a specific denial.
There was a profile claiming to be a co-founder of Mastodon yesterday. It looked and smelled funny, I did some investigation. Eventually Gargron made a statement that there was no such thing.
The account's toots started disappearing, and someone claimed that it had been stolen from him (or copied, not sure which).
It becomes a test of truth -- consistency and correspondence are strong tip-offs.