I was corner tanking Boarrior as Woodie and it knocked me out of the arena with its spinning attack, where I ended up finishing the fight solo... definitely a buggy run. It was the bottom corner of the west gate if the spawn gate is north, if that helps.
Steps to Reproduce
Tank Boarrior in the corner. Wait for it to use the spin attack, it may knock you out of the arena.
Status: Known Issue
We are aware of this issue and have it logged internally but either we do not have a fix ready yet or we are not planning on addressing the issue in the immediate future.