Well, there's the proof that different people use the game differently and so things are discovered.
I always research explosive warheads to max level before bothering to build mines. It's cheap, and I know the mines will have to be useful for a long time -- and cannot be upgraded. So I would have NEVER discovered this odd little behavior. Hopefully it will be easy to change how mine damage is calculated, and it ought to be changed or else a cruiser stuffed with Organic armor will be the ultimate minesweeper.