The range at which you drop out of combat in PvP is extremely far. Remember to take into account anyone you hit or anyone who hits you, you're essentially 'in combat' with them. An aggro in a loose sort of sense.

In Slaughter mode you'll get hit by so many things that the 'aggro range' basically covers almost the entire center platform. In order for you to Hide again you would have to go down the stairs and maybe even more.