My riding instructor told us this story last summer.
She was at a high-level horse show with one of her students and just one horse. This horse is completely awesome, but rather high-strung. Instructor has been using natural horsemanship methods (think Clinton Anderson and Buck Brannaman, if you're a horseperson) for the last year or so on all of the horses in the barn, which is very unusual, since it's a hunter-jumper barn. So we can all understand how the observers wouldn't know what she was doing.
At the show, the horse got emotionally overwhelmed. He was jumping, bouncing, snorting, and generally kicking up a fuss. He's fairly young, and this was the first show of the season, so Instructor and Student decided not to push him. Student took off his saddle and bridle, and Instructor worked with him on the natural horsemanship methods until he calmed down a bit and turned his brain back on.
They let him relax and eat grass for a while, and then went to put him on the trailer. He refused to go on the trailer, and started bouncing around again, which was not unexpected.
In the horse world, most people are willing to help with a fussy horse, because we've all been there. However, many people believe you must force a horse onto a trailer either by hitting him until he goes on, or by putting a rope behind him and physically placing him on the trailer. Instructor politely refused all offers of help, and just started letting the horse figure out what was wanted. When he calmly walked forward towards the trailer, she let him stand and relax, but as soon as he moved away from the trailer, he must trot or canter in circles. He figured out fairly quickly that he got to rest when he moved towards the trailer, and began to willingly put his front feet in the trailer. However, he was still nervous, so he still backed out instead of going all the way in.
About the third time he put his front feet in the trailer and stopped there, someone who had been watching (who had no connection with either Student or Instructor), lashed the horse with a whip. The horse of course panicked, thinking "I KNEW it! There IS something horrible in the trailer, and it just grabbed me!"
Instructor told the guy exactly what she thought of him, and it took another hour to get the poor horse in the trailer.
(Horse is fine, and after a summer of training jumps like a dream and loads in the trailer beautifully.)