Apparently, even the crabman can slide back after return fire: I exposed an assult to flank a shield and gun crabman, which was under the cover of its shield. It didn’t kill it for two HP, and I was hoping to finish it with another operative. But, after the return fire, the crabman moved back behind a corner, showing the shield to my flanking man, while being covered by a building in respect of my other operatives. The following turn, the poor flanking guy died.
I will report it the nex time it happens