Ideally you simply couldn't destroy them at all, though there might be situations where some mega brain placed them really badly.
However, in no situation should you be able to take damage from your own mines/claymores if an ally shoots them. That's literally a griefer trap.
And yes, I had some 9yo chase me down to shoot mines as I place them.
Sometimes it also just sucks when your pepega allies toss a nade or RPG down the hallway you're protecting, triggering a mine and killing you in the process.
It also just sucks when you have virtually blind people come up the stairs and shoot your mines, not seeing the green marker.
Which is especially funny because they're shooting them at a range that would be lethal, had it been an enemy mine.