My first thought was that when you put the tire on that you had part of the tire bead pinching the tube and it simply failed because of that. However you say that your tire came off the rim so that makes me wonder if the replacement tire is just the wrong BSD. Especially since you allude to having witnessed the tire being evenly mounted all the way around based on the white striping.
Still I suppose if it was the former issue and just the tube pinched between tire bead and rim that it might come unmounted during the failure. However the only times I've ever had a tire come unmounted is when way way overinflated to around 150 PSI or when I didn't actually have the witness line properly witnessed and that also involved being near the max recommended pressure of the tire.
Despite what ever the cause, it's basically poor practices. So pay closer attention next time.
Last edited by Iride01; 08-14-22 at 12:18 PM.