Possible Bug

[FLG]

I had 2 engineering units in the same hex creating a bridge on the same hex side. They both created there bridges together on the same turn. As one bridge was redundant I ordered one unit to start bridging operations to remove the bridge. The unit immediately dismantled the bridge and was available for moving with full movement points.

Is this a bug or a design feature? In this scenario, bridge building typically takes 2 or 3 turns.