Yes, the noise could have caused the deer to spook. I still shoot a TM Hunter style rest and the metal prongs make a slight noise when the arrow is drawn against them. I am not fond of putting moleskin on it to silence them or any other fabric and I usually just put a tiny drop of synthetic oil(scentless)on each prong, works like a charm, no noise. One afternoon this past season I forgot my pouch with my little tube of oil in it, no biggie, until I tried to draw on a doe at 14 yds. She was looking away and I had good cover and as soon as those prongs made that noise she bounded off a few yards(without ever looking),she stood there with here head turned around and her ears dialed in like a radar in my direction. I had no shot and she slipped back the way she came about thirty seconds later. So yes I think an unusual sound at the wrong moment will spook them, funny thing is 25 minutes later a buck came in and never even noticed the sound (he was busy making a scrape and hooking some over hanging branches, soI'd say he was a little distracted)and I killed him at about 17 yds. My dad shoots the WB and loves it but itmesses his vanes up a little (but in the interest of honesty his setup is definitely in need of some fine tuning IMO).