If he is not asking for referral fee, then no point of giving him because he probably don't need it!!!
In this business, we do a lot of things that are not absolutely necessary.
In the case of paying a Referral Fee . . . . if you'd like the Referring Party to consider repeating that behavior, then I'd encourage it. If you don't want him to repeat, don't pay anything. Just do what's right.
It's just like watching a dog or a horse behaviorist . . . . and choosing between a carrot and stick approach.
The carrot usually wins.