I was having fun in Endless mode one day, chopping endless amounts of robots to bits, when i died on level 16. It was one of those Titanium progressive 3-stage jump pad levels (the blocky one, not the building one).
Suddenly, out of nowhere, 3 of the mk 3 sword robots came up to the platform that i died in, and started swordfighting over my corpse.
I kid you not, this image is proof of them fighting each other.
Before you ask, yes I did put this in the bug report thread. I just thought it was funny that they malfunctioned like this.