Yeah, I'm very curious where Darcy found that out, too.

I know most bosses don't drop their green(s) every time they're killed, but I've always thought the AI players had the same odds as the humans for getting a green drop assigned.
And as for Rotscale, I'm used to either him or one of the Rotting Dragons dropping the green bow every time with a team full of eight humans. Back before heroes and HM, etc., I used to go on Rot hunt parties with friends. Once we had a team of people/builds that could kill him, we'd just kill him and rezone over and over until everyone that wanted a green bow had one. Usually someone would get the bow more than once, but it was a team of friends so sharing wasn't a problem. We always got one bow per island clear, from Rot or the dragons. Since heroes arrived, I've killed him once or twice with parties including heroes. We didn't always get a bow when the heroes were there.
If people have been 600/smiting that island and not getting the bow each time, I wonder if the drop rate has changed or if it's a special case where the code changes for parties of less than six or eight members.