Tuesday, the day of the patch, I was running around STV doing quests and one of them had me getting reeds from the Nagas there. I would stealth up behind them, sap them and then pick their pockets. I noticed, what seemed like a fair number of times, that sometimes I would go to pick the pockets of the mob and I would get a message along the lines of "pick pocket has been completely resisted" and I would drop out of stealth. This wasn't limited to the Nagas. It happened on various other humanoids through out the day. I can't say I remember seeing that message and completely dropping out of stealth for a failed pick pocket seemed new to me as well.
It's possible that it's always said that and I am only now noticing it because of the new combat log. Wednesday I was picking pockets left and right and don't think it happened once.
Unrelated but how often have you found that vanish didn't remove you from combat? Tuesday I did Van Cleef and killed him and some of his guards but I figured I would just vanish and split mid fight but when I vanished they still kept hitting me. I ended up jumping into the water and thought I would wait until they lost agro on me but I forgot that in instances the mobs don't just give up and I ended up with every mob on the boat coming after me. lol I
have had a dot on me before that made vanish wear off immediately but there was nothing on me when I was doing VC.