Managed internal collision check returns coplanar faces - how do I distinguish coplanar from intersecting?

[Moult]

If I have 2 mesh boxes next to each other in a collision manager, which share a coplanar face, a managed internal collision check result will show that they both collide. This is technically true, I guess, as they are coplanar. Is there a way to distinguish between whether or not they are simply coplanar, or whether one is actually embedded a certain distance (given a tolerance) inside the other shape?

I'm running this with Python-fcl but I figure I'd ask here as it seems to be unrelated to Python bindings.

[SeanCurtis-TRI]

Can you share the code snippet so we can make sure we're having the same conversation?