I only ever worked for small outfits...my experience is, that with htese types (and that is with a lot of assumptions on my part since it is very hard - or rather impossible - to 'know' what type he is and you are from just a few words) you have them make their mistakes. If it was indeed a small issue and he would not accept your advice, let him go ahead and then talk about it when on the ground.
Also: quite a lot of times one does not understand how one comes across - I have people tell me that they felt I was aggressive when I was not....