The secret is that we are all idiots. Some just refuse to recognize it and act like jerks because of it. None of us actually "know" most of what we know. It's

The secret is that we are all idiots. Some just refuse to recognize it and act like jerks because of it. None of us actually "know" most of what we know. It's unprofessional to start calling names. It's generally uncouth to even start the argument unless you have really strong evidence and can back off when that proves insufficient. Don't be bothered when they don't have the evidence to back it up, but when they do have the evidence fix whatever caused them say it and keep some evidence.