I figured this would have been reported already, but my search through the forums and the known bug list returned nothing.
This bug is simple, a Loki frame can essentially walk through most walls. He just has to cast a decoy against a wall and then switch with it. The result causes the Loki to clip into the wall and go either way.
Here are screenshots I took of the process:
Not much use and not really gamebreaking, but a bug is a bug and should be fixed, despite how fun it can be.