Chuck Norris is one of those folks that is so much larger than life they can get away with most anything without anyone thinking much of it. Others in this category include Sly Stallone and Steven Seagal. Everyone knows they are waaaaaay out there ... at least on screen anyway. They are all also willing to play up to their "characters". That's kind of their charm.
I think the ad is kind of lame too but at the same time I laughed a little bit.