That's about Eye Blob Demon. While his eyeball is heading after us when killed, press pause, then resume - eyeball disappeared. When game is paused for short, it seems eyeball was through our character (but is not hit). In other words, not all things is freezed when GG2 is paused. I haven't tested it yet, but I guess, similar "sprites" like butcher's cleaver (when he threw it), or even bullet shoot from our/enemies weapons have the same eproblem. I have the newest version on my PC.

EDIT: I discovered it today when I was playing in hell version of a prison in Endless Mode.