Coves - twin bosses, one is "lost"

It happened for me 2nd time in Coves map with two bosses - one with prophecy Deadly Twins, other one... I'm not sure, maybe prophecy, maybe map mod. There is always golem and his pirate. With two bosses in the boss "area" (that place where gold lies) I found one golem and two pirates. In both cases the 2nd golem was somewhere else, far from its area. Screenshot shows the recent encounter.

It didn't follow me in both cases, it was just there - I'm sure about both cases.

Bug number on the screenshot.