I think it has to depend, as AnnaStrophic has inferred, on what relationship you have and what you wish to have, with this man. I once worked for a man I respect greatly, even years after he left. The one thing that nearly gave me brain bleeds was when, in meetings with colleagues, parents, "underlings" and so on, he would say, consistently, things such as "I have a pacific idea in mind." I could not bring myself to correct him, even anonymously, and I never will, even though he is no longer my boss and I have "nothing to lose". It just seems the wrong thing to me. Perhaps it is because I imagine it would be a greater to hurt to him than him going through life misusing the word. It didn't affect my respect for him (although I didn't like it!), so I imagine most others forgave it, also. :0)