I don't know if ESTA is still involved, he explicitly said his ESTA applications were denied in 2017 and that's why he applied for a "tourist visa" and I don't

I don't know if ESTA is still involved, he explicitly said his ESTA applications were denied in 2017 and that's why he applied for a "tourist visa" and I don't think ESTA applies to that in any way. But he's a smart enough guy to read the limitations of tourist visa, I wish him the best and I hope I'm wrong.