Floating Death Bug? Exploit? Who the hell knows. I like to think this a feature.

After mines are finished with their amazing physics upon placement, they are forever bolted into that location.
This normally doesnt apply to gameplay, but two times when this happens is:
1) placing mines on walls. I bet turrets work just as fine.
2) placing mines on map sided buildables.

A minor thing surely, however its quite awesome to have a (escort 3rd flag) 9 mine that doesnt go off right away and you can fish for that vehicular multikill.
Im not adamant about it, but im pretty sure even if the driver(or as im led to believe, anyone in the tank) has defuse, a dude in the turret can still trigger them. Awesome.

Still, you probably want to fix it. Sometime.

 

What about them?
Sure, mines are perfectly fine having a pixel of ground to lay on, but this has more to do with them actaully levitating in air.

 

Guess it's to save physics simulation time. You would periodically have to check every mine on the map, if it still has something beneath it. With a potential of 512 mines it should be doable.

Until then you got a frozen version of a Bouncing Betty

 

Works in dropping them in seat two like the brenodi apc.

 

Yes, in an older version they didn't attach themselves to a surface in the way that they do now

 

The last part you noted -- about the gunner of a vehicle being able to explode a mine -- that is easily fixable. The mines reapplying physics to themselves though...less easy for me.

 

Just tested this with an MG turret and a wall, when recycling the turret / wall, the mine just drops to the ground?

 

If you get in the turret seat of a vehicle then place the mine on top of the vehicle, wait a few seconds then drive off, the mine stays in place.

 

I can't seem to reproduce this, but I've added some code to check for it nonetheless.

 

I believe they are meant to attach themselves to whatever surface they are placed on after x seconds of delay

 

I know, I've stepped through the code. The relevant bit is this:

Code:

if (tr.m_pEnt->IsPlayer() || tr.m_pEnt->IsVehicle())
		{
			SetThink( &CNFMineGrenadeProjectile::PreDetonate );
			SetNextThink( gpGlobals->curtime + 1.0f );
			return;
		}

That says: "If the mine is on a player or vehicle, don't stop moving yet."