How would you have handled this driving class?

sometimes a runway can end up ok.. but once the horse has been in an accident.. they are ruined as a driving horse.. being trapped and having no way to escape is terrifying for any animal.. it takes alot of trust to be a driving horse.. if you think about it.. how un-natural it is to have a big clunky thing behind you and not being able to see it.

That's not true. I drive regularly and work with a professional trainer in the Carriage Driving world. Many horses have accidents and come back just fine. The horse that was lying on the ground, tangled in the traces, was a Youth National Champion in Driving the next year. My trainer worked with a Friesian mare that was in a bad driving accident, the cart she was pulling was destroyed. The mare never had a problem with being driven again. She had a very few spooky issues, but she had more issues when she was being driven by someone with no confidence. I firmly believe that more drivers have problems after a crash than the horses do.

Driving does require a great deal of trust between driver and horse. The training process should be slow and steady, building the trust before the horse is ever hooked to anything that could cause damage. Spending a lot of time with ground driving in a blind bridle and good old fashioned lunging in a blind bridle can be the key. The horse needs to understand voice commands and be 100% steady long before training shafts and weight are added to the harness and way, way before a cart is put anywhere near the horse.

My 10 YO mare was trained to drive over a 3 month period. She was very broke to ride and had extensive ground work on her with a blind bridle before the trainer ever started with her. We went to our first show in driving this last weekend and got a 2nd and a 3rd in our 2 classes. The picture below is her first drive in a heavier cart, with my trainer driving her. This was almost exactly 90 days after she started in training. (By the way, she's a purebred Arab)

This is only true to an extent - most of the time the horse will remember the runaway and will be nervous, or looking for the next oppurtunity to do it again. Depends on the trust. I have been on a carriage twice when the same horse has run off with it (I wasn't the driver, only the groom) as we were warming up for driving trials, the horses where in tandem and they always used to 'scuttle' for a hundred yards, and then they bolted out of the blue several times because they could, once landed the driver in hospital, the next landed me in hospital, and the time after nobody was hurt. They weren't used as driving ponies again and were sold as ridden ones xXx

To tell you the truth, I'm paranoid and always expecting disaster to strike in events like this. I probably would have gotten off and just held on to my horse.
When panic strikes and a disaster like this happens, it happens so quickly and everything so unusual happens so suddenly, I dont know that you can really make quick enough, rational decisions.

Really sad and unfortunate for those poor horses and the stupid handlers involved.