If that happened I would actually directly ask the other interviewers "Did I do something wrong or say something to offend him/her". Put the ball in their court and hear what they have to say.
I also love swat535's suggestion to end the interview with "Thank you for the opportunity, I don't think I'm a good fit for this position"
Also, you are right, I'd treat that as a data point into whether this is a company you want to work for.
I once had a company ask me to interview (one of their recruiters reached out to me) and I was so so on it, but curious, so I took time off and scheduled a technical phone interview. 5 minutes after the interview should have started (I was waiting for the phone call and wondering whether I had messed up the scheduling), I received a brusque email from the engineer meant to interview me "I don't have time to interview you, reach out to our recruiter". You can bet my interest in the company tanked and when the recruiter tried to re-schedule me (without so much as an apology) I declined and ask they not contact me in the future. Because I figured either.
1: They hired jerks 2: Their engineers were so stressed that they viewed an interview as yet one more burden.
I have been on the other side where a candidate we were interviewing (at the time I was a junior engineer and my interview partner was a Senior engineer). The candidate was so rude/condescending to her (but not to me, I wonder why) that after we finished our interview session we told HR and they cancelled the rest of his interviews and thanked him for his time.