Oh, and on the actual question that started the thread:

I am an inveterate picker of nits of all sorts, and this would drive me absolutely nuts. But I have to agree with bill - if you can handle it in an exceptionally diplomatic way, and if the recipient of the correction is a stalwart soul in a tireless quest for self-improvement, then you might not sour your relationship with the person - but it'll still probably backfire.

I had a brilliant professor once, extremely articulate and in solid command of his language skills, whose great fault was that he said "anthropocentric-centered" - and he found more occasions to use it than you might think. I wrestled with how to correct him for a long time, talking about it with classmates, and in the end decided he would probably be okay getting through life with that one truly annoying tic of speech.