Prior to this video being shot, Max may have taken a double dose of the assorted pills that truckers use to drive 36 consecutive hours. I can't be sure. It wasn't my day to keep track of him.
But, the point you should take away from this is how realistic that elephant's ass (probably) looks. With booty physics like that, it's no wonder Far Cry 4 ended up as one of our top games of PAX Prime.