Here's a quick thought...We brought one of the ponies in this morning and hadn't yet brought her a friend in, she was kicking at the stable door and generally being a nuisance.
Dad was helping with the yard (he's a genuine superstar) and said 'She's one angry pony isn't she?'. Our dad is pretty clued up on horse behaviour yet despite this he jumped to a conclusion that an anxious horse was an angry one despite plenty of evidence to the contrary.
How many people have done this? Been quick to be label the horse as angry or difficult, or to blame the previous trainer because they clearly did something wrong? Sometimes it's actually easier to just listen to the horse for five seconds.