The more I think about this, the more I think there may be some truth to it. In fact, there may be a scientific explanation. As an engineer, I can't help but consider the science seriously.
It is a well known fact that plant matter requires bacteria in the gut to break down the plant material. Meat can be digested without bacteria. The strain of bacteria affects the efficiency of the digestive process and is usually highly dependent on the host animal - different animals have different strains of bacteria in them.
It is also well known that various herbivores eat a healthy dose of adult feces in order to kick start their own digestive bacterial colony.
Bacteria are extremely small organisms that can be easily transported around in the air. That's why so many bacterial infections are spread through the air.
So, I'm thinking that it's entirely possible that SOME people might accidentally (surely not intentionally) be breathing in large doses of bacteria that end up in their own gut and thereby kickstarting their own colony of deer specific bacteria in their own gut which would then generate the same smells in their own flatulence......
Of course, this requires plant material in their own gut for the bacteria to feed on. Which explains why this doesn't happen to me. Yet another reason to stop eating foods food.
Various studies have also shown that the bacteria in our guts also directly influence our brains and thereby our behaviour. I am dead serious about this. Therefore, I advocate extreme caution for all those who exhibit deer gut odours in their own flatulential gases. It would be very unhealthy to start chewing your cud around friends and members of the family let alone chasing does around in the field with your nose down during the hunting season........