Give me one good reason

Why I shouldn't disfellowship you right now?

I remember being in a committee and having an elder ask me this question. It was a bit shocking, but meh, the guy who said it was an asshole. I knew a few reinstated folks who had a terrible experience with him as well.

I always thought it was a local thing, but I made some friends who got reproved/ disfellowshipped in other cities (sometimes countries even) and there always seems to be an elder who asks this question.

Is this in the elder book or something?