Summary:
Sometimes, the enemy unit is able to trigger a proximity mine without taking the damage, even though he's the only unit within its radius. It happens when the enemy unit is moving away from the mine just when it is about to explode.

Repro Steps:
Try to leave repeatedly leave the trigger radius of an enemy proximity mine just when it is about to explode (1.5 seconds).

Result:
The mine explodes, but the enemy unit doesn't take damage. This is erroneous since the trigger radius is identical with the damage radius.

Expected Result:
If the mine explodes, the enemy unit that triggered the mine should take damage in any case.