So sorry to hear about this!! Please take comfort from the words of others who have read this and know that you made a difference by making averyone a little more aware of the ignorance of others. My heart goes out to you and Rohan!
Sorry to hear of this outcome, as others have said I hope that the loaners dont get off scot free! Do what you need to now legally, give yourself some time to get your head right, then persue.
I'm so sorry, but please don't lose hope loaning a horse again - not all loaners would be like that. I'm considering loaning my horse as a broodmare (she has injured herself and could do with just being on the field), but will most likely keep the insurance. At the same time, I am looking for a loan horse and would ensure that whichever horse I pick will have a great year or two with me.