If that's what I were worried about then I think I'd just leave it at, "we didn't feel like our personalities meshed well" or "we don't think you are a culture

If that's what I were worried about then I think I'd just leave it at, "we didn't feel like our personalities meshed well" or "we don't think you are a culture fit" and leave it at that. "Aggressive micro-expressions" sounds aggressively silly.