job interview question

so I went on a job interview today for a position that seems interesting to me and I may enjoy. the only strange thing I saw was he said to me "people aren't really that nice here" he continued to say that his boss curses alot. what the heck does it mean where people are not nice in a work place, ya don't have to be friends but what?!?! also he asked me what I would do if a coworker started to argue with me? so I said I'd let the purpose talk it out. but what is the deal, who is arguing and what not in a work place.. I get you can disagree with a co-worker but not being nice and arguing ... is this a red flag?