Not only misplaced animals and incorrect procedures, but when supposedly intelligent characters do something that makes you say "that was stupid - why didn't they just do this", etc. I think part of the reason I hate it is because we have all seen so many TV shows and movies about so many subjects that we have little real experience with. When you see things repeatedly presented as reality, it is difficult to really and truly understand that it is only fiction. For instance, I have some experience in the natural world and in the health field, so I can often see the mistakes there. But I have no experience in many other fields. Example: I have seen LOTS of court type shows and movies, but have no firsthand experience. So I would have to tell myself not to expect my media "experience" to be real if I ever have to be involved with the system in real life. But if the media is my only experience, I think it would be difficult not to somehow expect it be similar to what I have seen, no matter what I tell myself. And many people may not think to tell themselves anything at all.
That is the downside of these silly reptile "monster" movies. WE all know how goofy they are, and most thinking people will realize it is all fiction. But if they have no exposure to real herps, they will have no basis to know how much is fiction and how much is taken from some real live reptiles.
Sorry to be so long winded, but it really irritates me to pay good money for a movie and see people doing really stupid things.