I already easily noted that legendster had very bad OpSec practices overall, but that doesn't mean he is high risk to trade with and worth tearing his account apart. Its common to save data online and forget about it if you don't use the same medium the most.
Saving private keys in e-mail drafts should not be "common" for a trustworthy person on this forum. Getting one's e-mail hacked and forum account compromised literally means you can't trust the user to be who they claim to be.
About, his comprised email and private keys - He could still have access to his old telegram handle which he has posted here many times. So, it could still prove the account ownership.
Right. It's not like any scams or any other sketchy shit ever happens on telegram. No one ever complained that they got deceived on telegram by some impersonator. We should definitely start using telegram for Bitcointalk account ownership proof because this can't possibly ever go wrong.