It is possible to get down from a stand and leave the area undetected, I've done it many times.

If a buck sees you of course he's alerted to your presence. A deer isn't like a light switch, either on or off, there are many variables that attribute the accuteness of their alarm. Like humans, you see a shady looking person standing on the street between you and your parked car. No visable weapons and he's not doing anything out of the ordinary. Do you .... A) Run terrified in the opposite direction for your life
B) Circle quietly around
C) Cautiously approach keeping an eye on him.
For deer, the higher the degree of alarm, the more drastic the method of survival is. This is the same for their memory too. If you shoot at a buck and slightly wound it, there's a good chance you won't see him from your stand for the rest of the season. If he busts you in your stand, you may or may not see him again from your stand and if you do, it will be from a safer distance. He will be eyeballing your stand. If he sees you walking out in a calm non-threatening manner, he'll take note and be cautious, but chances are you will see him from your stand because he don't know where it is. Although he may back track you to your stand. I've seen proof of this in the snow.

Deer are like people in that they all have different personalities and different tolerances for danger. In most cases, does, fawns and young bucks, 2 1/2 and younger will usually try to verify two of their senses to confirm their suspicion of danger. For bucks 3 1/2 and older they only need one sense to be verified. The older bucks only need a suspicion, no verification. If somethimg doesn't seem right, their out of there no questions asked. I believe that there some bucks that won't come out until after dark and never expose themselves to danger. Their survival is of the uttmost importance, even more than breeding.