I saw one of the most accomplished physicists in the world unable to solve a (hard) first year Physics problem in Office Hours. He did it three times and got th

I saw one of the most accomplished physicists in the world unable to solve a (hard) first year Physics problem in Office Hours. He did it three times and got three different wrong answers, threw the chalk down and walked away and asked us to come back tomorrow. Does that mean he’s not qualified for his job?