Used as an expression for avoiding or escaping a controversial scenario or a problematic situation by using someone/something else as an excuse to save your own ass.
Exemplified by the youtube clip "Douchebag Bison"
Akin to 'throwing someone under the bus' or 'passing the buck'
Reporter: Why do you think your movie was a flop this week?
Lead Actor: The script was good. But people just won't go see the film cause of the lead actress and her low level of acting skills.
TV viewer: Damn! That dude just gave her a bison nudge.
example #2: Penn State gave Joe Paterno a bison nudge.