I guess what would bug me is -- why on earth would the vet even make that comment?
If he's saying it to slam the other vet, that's pretty unprofessional even if it's true.
If he's saying it to pat himself on the back, that's pretty pathetic, really.
In any case, I'd let it go, because this IMHO can be a sign of a passive-aggressive snark in development (by the vet, not by you), and I want none of that, thanks.
You don't have anything but this one random comment to base your concern on, and people say all kinds of stupid stuff that isn't backed up with facts or anything real.
One thing you might want to keep in mind as perspective: there are LOTS of vets out there; you are an EXCELLENT client and your dog is not a problem patient; if some fool has put a black mark in Max's file, rather than try to erase it, you'd be better off looking at moving to a vet who's not such a dork.
Now, this is all speculative, since we don't know that any such thing has happened -- but I sure don't need my vet's approval of my dogs, my vet needs MY approval of HIM. And that's just a fact.