Or standing in front of a champion GIANT I press tab and get a risen bull. Than a chicken. Than a grub.
Or how about pressing tab, pressing 1 and you suddenly get hit from behind because your focus target is 180 degrees behind you. Im not kidding. I dont even have a clue how I could attack it. Happened 3 times so far.
Tab targeting in mmorpgs never works 100% but in gw2 its really bad.