There no evidence about that. That's the problem. But we have evidences that I'm still myself. Called "signed message". If account would change hands in 2020 i doubt that he could sign message with an address from 2017-2018.
It wouldn't be the first time an account was sold along with a private key that was used some time back. I'm not saying the claims that the account changed hands are valid, the evidence is very weak. But, if you proved to the community that the claim is total horse shit, then maybe JollyGood would feel pressured to revise his tag. I personally think his use of the trust system is abusive. A hair trigger with red-tags is damaging to the system as a whole, and dilutes the value.
I have to say; in my opinion all the red-tags on your account are worthless. My trust settings only show the ones from JollyGood and bob123. The one from JollyGood shouldn't be there at all, and the one from bob123 is taking a hardline stance on semantics.
I see that KTChampion's feedback shows up on DT. I get the one about bounty cheating, and not believing the "Friends" excuse, but that's another situation where I don't like tagging people unless there's substantial irrefutable evidence. The other one is just another petty squabble using red-tags as a bludgeon. My recommendation to you is to not feed into it and make things worse with retaliatory feedback. These things have a way ironing themselves out in the long run.