Youtube takes an age to loadon my slow connection, so not even going to bother to try and watch, but from the replies Ithink I know how this went. I've seen it happen with my own eyes done by people who works on our farm, despite me trying to teach them differently. Horse is cornered o rput into a crush or some such place where it can sort of be controlled. Some form of bridle is then put onto its head. Horse already wants to freak out becaause it's probably never even had a halter on, then it is manouvered in front of the cart, a harness of some sort put on, the other horse is then given the cue to move off, after all the passengers and everyone has off course gotten on, and the poor confused unbroken horse starts to fight for what I can only imagine it probably feels is its life, which then usually starts the other horse off too and all hell breaks loose.
Strangely enough I've n ever seen anybody get seriously hurt during this process. The worst injury I ever saw was actually a realatively well-trained horse and mule team, The mule spooked at something, started kicking and bucking in and broke a part of his harness. During this process one of the passengers, being less than sober started falling off the cart, instead of his friends rather leaving him to fall free, grabbed a hold of him. Only problem was his foot got stuck in front of the wheel. It was several metres before they finally brought the cart to a standstill, in the meantime he's foot is draggging on the very rocky ground. He very nearly lost his foot.