[Slick]

I haven't done testing per se, but I have seen allies co-mine a sector in multiplayer games several times. I have never seen ships survive as you have described. Could it be that you laid the mines in the same turn as the ships arriving? I can maybe see this situation if your ship laid mines after the enemy ships were already in the sector. If this happened, they would not be engaged by the mines. Engagement of a minefield only occurs when entering a minefield sector. If they get laid (no pun intended) after the enemy is already in the sector, then there would not be an engagement.

Slick.