I'm absolutely emotionally destroyed, but I have to know...

I got a juvenile bumblebee ball python 3 weeks ago. He shed on wednesday, ate on friday, we left on Saturday morning, and when we came back Sunday night, he had thrown up the rat and died under his cool side hide. He was about a year and a half old. The previous owner is a good guy who I know I can trust who had him in a rack who regularly breeds BPs. The temps were good (89 hot side and 77 cool side) and I know they didn't dip because the digital thermometer I got records the highest and lowest temp and it never dipped below 87 hot side. The lamp bulb was 4 inches away from the screen. He would calmly put-put between the hot and cold hides once or twice a day, no darting around or trying to find a way out. The shed went fairly well, it came off in 3 pieces (one big one and 2 small pieces) and I checked his eyes and nose for any stuck shed with none to be found. He was about 2 and a half feet and ate frozen/thawed small rats. He never had any problem swallowing/eating. The humidity was 41 percent ambient with a humid box filled with damp moss. He had fresh water that I changed every few days. He never showed any signs of stress and was completely tame while handling every couple of days. I'm really worried, I got my first BP 2 months ago and my third one just last week. I spent probably 15 to 20 hours reading care sheets, forums, and video tutorials before getting my BPs. But none of that changes the fact that he is sadly gone now. Am I just a bad snake owner? Did I kill my snake? Should I be trying to find other homes for my 2 remaining BPs immediately before they die from something I did? Or was this just an unavoidable and horrible accident. I don't want my BPs to go anywhere, I love them already, I haven't had them long, but they're already my babies. I just sat on the floor crying for a good half hour after I found him, and I am not an emotional man.

Please advise honestly. Am I a bad owner who should accept my heartbreak and re-home my BPs for their safety, or was this not my fault and something I don't have to expect with my other BP babies? I need to know honestly, I can't be responsible for more BP deaths if it is my fault. I'll hate myself forever. I love animals, I have had multiple species of pets my whole life, but this is my first time keeping reptiles.