I am after a 9pt that myself and a friend have seen three days in a row @ 4pm.
Today my friend setup a decoy of a buck on the trail that the 9pt uses
when he came in and saw the decoy he froze, stomped the ground three times then ran the other direction. My friend says that he is spooked and we don't need to go back to this area for a couple of days to let the buck start using that trail again. I believe since we are hunting in a suburb area approx 6 acres that the buck is going to continue using this area there aren't to many other areas to go and the fact wasn't spooked by a human.

Any and all advice appreciated.

Im sure your Buck travels outside that 6 acre area but it must be his home ground if you see him the so regular. If no one else is hunting the area it would not hurt to give the fellow a day or two to return to his natural patern.

When he returns is not as important as how you use the decoy.
If you're going to use a decoy I would not place it on the trial. Further I would use a Doe decoy over a buck this time of the year.
I'd place the decoy so the the Buck you are after could see it and wind it from the trial but so the it causes him to stop and study it within bow range of you stand.
There are several different doe in heat jells and scents out that can be applied to the decoy. Clean the decoy before placing it and appling any scent to it. Place the decoy up wind of your ambush sight so it is visable and the wind carries it scent across the trial so the approaching Buck will become aware of it and stop to study it.
Your Buck may have been imtimidated by the unknown buck in his home range, whereas he may become interested in a Doe for the obvious reasons.
Good luck and let us know how you do on the hunt.