Most painful/hurtful words

Thank you for applying to this position. Although, your skills highly match with what we are looking for in a candidate however.......

I might have innocently said something very hurtful to this guy as even after 20 years his nostrils started flaring when he saw me. I met him at a social gathering, he was bitterly complaining about the west and just gloating as a senior Airforce officer his life was so great back home and I was really confused and asked him that if he hates it here so much and if he had such a great life back home than why would he not go back, I thought it was a fair question but the guy just lost it and is still pissed at me after 20 years