When I was 10 years old, I took in a stray puppy because hey that's what any caring little girl would do. What I didn't know was this poor unfortunate little lost soul just happened to have distemper. The horror of going through losing 3 dogs over what I thought was an act of compassion taught me the most valuable lesson about quarantining animals. Of course 10 year old me didn't know at the time how that would impact my life but I have never introduced a new animal to existing pets without isolating them since.
I am so sorry for your loss no matter the situation or the cause. It is heartbreaking to lose a pet and even more so when you do not know what you could have done to possibly save them.
I do hope you learn the lesson of avoiding big chain reptiles at all costs and I also hope this does not sour you on reptile husbandry because these animals are amazing and are worth any effort.