Firstly im sorry you had to go through that,
Watching your pet deteriate beyond your control is the most frustrating, and upsetting things that can/do happen..
Apparently its a neccesary part of learning how to keep reptiles,- hard lessons if there are no answers, -Cant perform on necropsy accurately on body tissue/fluids/ect after frozen.
TOXIC SHOCK
Toxic shock causing death in humans, usually comes about through, the circulatory system shutting down organs, (ie: from strep,or septicemia ect.)
Whole system is 'septip' due to chemical,/ and organic toxins,
The onset of septic/toxic shock would be,- very high temp, vomitting, lethargy, painful, slight rigor,the organ shutdown. This can kill a human, in 24-48 hours. ( thought this may help)
Had a similar thing happen my self,-diamond several years ago,.. and made the mistake of freezing the snake.-( A necropsie wasnt done, even though i had a Vet lined up), -(I still have the diamond snake body in the back freezer, -i should get 'rid' of it soon i spose.)
Vet's can perform certain, pathological test's,and gut contents can be analized,- but im pretty sure, results can be inconclusive, and that sucks even worse.
Mine had an injurie,. then about 6 weeks later, went 'puffy' , had a meal, then went into yawn-like seizures. It was quick though,- no consolation.!
Hope you recover, and try not feel guilty, -you seem to have done all you could under the circumstances.
Sorry once again.