Didn't get to test this too much, but I haven't noticed anyone mention this.
It seems you get caught up in battles while trying to sneak in, even if you were not in there sight. It's as if the enemies have a 360 view.
Also noticed if one gets caught, while other characters are decently far, they get caught up in the fight too.
This was with the recent patch. I noticed they fixed the biggest problem of activating items using AP though so thats good :)