I don't have a lot of experience with thin-wall rims (if that is indeed what you have), but 85 PSI doesn't seem to be enough pressure for that kind of damage at the primary break. The clean break was incured my the sudden stress loading that the first break caused in what remained (for milliseconds) a tensioned wheel.
If the tube went, the metal damage on the rim would be blown OUT, not folded inward as shown in the pics.
To quote one of my trainning offcers may years ago, "sure beats the hell out of me!"
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