During the first long raid (Molten Core) the loot table had a weird deviance of being very similar depending on the player that created the raid, Blizzard said that was impossible but in reality guilds would just rotate the raid leader until they hit someone that "would", for example, drop the legendary bindings and stick with that RL for a while -- it worked for many people and 4 or 5 years later one dev finally answered the big question: "Is loot defined when you kill the mob" or "is loot defined when the raid is instanced" which is the second option, the sum of these plus some weird bug that they might have fixed silently at some point might have caused the RL rotation hoax.