To sum up what some who have reported this bug did, I made a sample of how to do this perticular bug.
The enemies happen to be friendly... I mean confused or unable to hit the player again under close distances and if the player sits on two of them they will try to rotate to get a glimpse of the player. To replicate it, simply close up or jump to the enemy while in invulnerabilty phase.
Love your games nevertheless! I aspire to be capable of doing this someday too, even if it takes years to learn it first...
PS: This bug is prevelent on every bug-like enemy in every level.