There is an exploit where in Arenas, BG's or whatever you may be doing you can "ignore" CC with a multi-passenger mount.
If the person in the passenger seat on a multi-passenger mount gets sapped or whatever CC, the driver is still able to drive them around safely avoiding harm until the CC wears off.
I apologize if this is a repost, I searched avoid CC, ignore CC, multi-seat mounts, and multi-passenger mounts and didn't see anything.