Possible exploit to avoid getting attacked by keep lord

[Ilvari]

I was standing near the keep lord waiting for a siege, when I suddenly got attacked by a WE. I thought the keep lord should immediately oneshot her, but it appears that player has a trick to make the lord ignore them. As you can see in the screenshot, the regular guards are attacking the WE but the lord is just standing around and doing nothing. I'm pretty sure there's a cheat involved here.

[Zxul]

Been like this forever, if you unstealth while on top of lord the lord won't attack you. Very nice to gank those that think afking inside keep is a good idea.