To me it seems you gave the option of two bad choices. Take an unsafe shot or do something unethical. That being shoot the deer and have your friend tag it as your own. Both of which are bad choices. If the deer sees you does not necessarily mean you are busted. Stay very still he may stick around or move in your friends shooting lane. Or he may just wander off because he doesn't like what he sees. He'll be back. My friend was scouting one morning and came accross a buck which saw him but didn't wind him. He has seen it a couple of times in the area since.