I saw that one as well. They took off because they thought they would be beat on, I guess they thought it was their fault because the biker was an idiot and tried to pass on a turn.
I saw on video where the guy tried to do a wheelie on a sports bike with a passenger. Needless to say she didn't know he was about to this stunt and basically fell off the bike in a forward face first motion. Ouch:small3d002: