It's pretty obvious, I think you need to buy the horse a waist harness..obviously he/she is struggling to hook in hence the damage. What size rig did he/she have up??
Also do you have the GPS track from their run??

My suggestion would be to buy a new harness (along with a couple of other small items such as a new rig and board)...it's not your fault if the horse can't get on the plane..but it'd be cruel to not let them meet their full potential.

Thanks for the advice. I think I need to get extra straps for the horse's board and a lesson or two on hooking in and out on the plane.
Horse did not have GPS on at the time but my guess the pulling back when hooked in could have re written the record books.
Horse was happily grazing soon after world record speed attempt- I think he knew he had it in the bag

Be glad he didnt pull the whole thing out , gallop down the road & cut a tendon..think of the upset ( wife? ) & the vet bills! + the pscychologically damaged horse..
Ps .. can I have your arena?
PPS - be glad the usual rider wasn't onboard when it happened or you would have had hospital bills too