In a human body, your lungs and tissues that come in contact with the smoke catch the tar directly. Remember, that cigarette tar in the video was filtered through water, then the water simply cooked off in a pan like any sort of simple reduction.

In the body, you take in the tar directly through your own filter, the bronchi and alveoli. So it's not like any water reduction/evaporation even needs to occur. What's occurring in the human body is more harmful, actually, because far more than tars are getting directly into the lungs and bloodstream. That inhalation/water filtration mechanism was fairly crude in the video and not meant to capture or demonstrate the full measure of what comes out of cigarettes. The lungs and their tiny air sacs filter everything they inhale at a mini-microscopic level, so they don't miss a bit of the carcinogenic nastiness that comes out of cigarettes.