A good example of how it's not so much the slip itself as the context in which it's made.
In the video, the preacher says "pinch his tits" instead of "pitch his tents" (which also happens to be a perfect example of the /I/ - /E/ vowel merger -- the preacher's vowel in "tits" is the same one for his successful "tents").

He then exacerbates his problem by continuing to refer to the audience's laughter, but this one was probably unrecoverable.

YouTube is a rich source of this stuff. Who needs Kermit Schafer, really.