I' d share this info with my friend, it wouldn' t matter to me which one of us bagged it if we ever did but I would sleep easy at night knowing I didn' t have any secrets from my partner. IMO Don' t taint the friendship with this share the info and even try to arrange to help each other bag this sucker..... i.e. have him push through one day attempting to drive the deer by you for a shot the next return the favor and push for him... and you know the pusher might just be the one to get the shot if the buck circles back..... never know till it happens but I' d at least share the info.... you never know your friend might just surprise you.
Best o luck