We were always briefed that the navigator should eject if a barrier (not cable) engagement was likely as there was a danger of the barrier top cable catching the AR probe and forcing it through the navigtor's canopy. Also, if memory serves, it was safer just to go rather than call "Eject, eject" as that would avoid the possibility of the second crew member getting a face full of Buccanneer canopy? Hence the navigator would make his own decision........