Bugged Jade Arena?

Anyone else run unto this? about one in ten times when I do the Jade Arena, the convicts dont become hostile when I enter the area. I think it has to do with the crabs, but im not sure. I know that i have witnessed the crabs aggroing against the convicts while the convicts were still green, and the convicts would kill it, then not become hostile to me. argh! very frustrating.

Yeah its a random bug that happens. I dont think it really bothers anyone so ANET doesn't bother to fix it.