Sorry to hear of your bad news Dan, gutted for you but at least you came out of it without any serious injury just a shame the same couldn't be said for your car. Can't believe no one stopped to help but sadly the driver pointing and laughing doesn't really surprise me, being a somewhat old git, I have noticed a distinct and negative shift in some peoples attitudes to their fellow human beings these days.
Not a fan of "budget" tyres myself so I can understand how you feel about the Fullrun, especially not good news on a rear wheel drive car.
Chin up fella, hopefully all will come good in the end for you.