I do believe that deer become slightly accoustomed to some human odors like cigarette smoke, gas & oil.
Think you're right as well arch308
There are many Metro Parks with thousands of deer in them and thousands of people a year walking threw them. Those deer are born in and are use to breathing air containing car fumes, tobacco smoke, perfumes, sweating joggers etc. Also the deer get too used to people. I used to run in a park in Reynoldsburg,Oh (Blacklick Metro Park) that you literally had to be careful while running/jogging down the narrow paths that a deer didn't step out in the path and you fell over it.
Not many country deer will ever smell those smells and the instant the older/mature deer do, they are alerted.