I actually just watched that movie yesterday!! And I was thinking the same thing.. Why the heck wouldnt that dog be freaking attacking those guys!!! I guess it was scared?? who the heck knows.. it just bounced around jumping lol. Well I guess dogs cant really act, its the trainers fault haha..
I thoguht that movie was kinda bunk anyways, as if she would just go on a crazy killing spree for no apparent reason lol.