can I ask why? If you are scentfree than deer can not smell you. Why add an unknow element?

If you are hunting in an area that is pressured and hunter A is using brand Xfox urine as cover scent. Hunter A spooks a deer while hunting, this was the mature deer you were hunting. Now the deer knows brand Xfox urine is bad, and may alter his travel route.

They above may happen it may not, my questions is why chance it?