In a DE bout, there is a group of fencers making a lot of noise by the side of the strip, trying to influence the director's calls (apparently the director is unaware of this). The director gives the command to fence. One of the observers calls out to one of the fencers, "(Name), look behind you!" The fencer does, reflexively, undoubtedly expecting to avoid a pending collision or object on the strip over which he might trip. There is none such, the crowd laughs, and the ref cards the fencer for turning the back on the opponent.
a) Should the fencer have been carded?
b) Should the observer have been carded for disrupting order?