A moderately famous physicist came to lecture at the university where Feynman was teaching. Feynman, a few minutes before the physicist had arrived at the lecture hall, read the notes at the lectern and spotted a mistake.

As the lecture was going on, Feynman apparently pointed out the mistake as if he had spontaneously identified it. The physicist, obviously astonished at that point, offered to stop the lecture if there was a mistake in his calculations. But Feynman asked him to continue, and apparently they became good friends later.

Schwinger and Gell-mann were pissed off because of two things - obviously they couldn't match Feynman's charisma, but they also felt he went around "generating anecdotes about himself" which contributed to that charisma somewhat.

Can someone confirm this story?