I wish there was something we could do to prevent these types of things from happening, but unfortunately I think it's impossible. More and more folks who are not tech savvy will be entering into the crypto world, and that means more people will be there in attempt to take advantage of them. I learned a few lessons early on, and luckily for me they were relatively affordable lessons.
Good catch finding this scammer's information, kudos for that. Hopefully he gets caught, and the victim gets his money back.
There's a (Dutch) name in his email address. That may be fake, or it may be real if he didn't plan on scamming anyone but took the opportunity when you offered it.
If it's his real name, it might be useful to track him down.
His username is a domain name, that may help too.