In this case it might be a case of being intimidated by a big agency. Isaac telling him that he was their smallest client had a "you're lucky we are willing to work for you" feel.
This feels even more dubious because if I figured out the correct company, they're fishing in the freelancer threads quite a lot. They know what they're offering to HN readers.
This would be first red flag for me. If someone from the getgo positions himself as doing you a favour, switch - it is not going to get better. At best its uncontrolled ego problem, at worst its a scheme to dry you up.
