That's definitely nerve wracking! I had something similar happen, with a 5D series camera and my 24-70 f/2.8. It flew out of a bag and landed hard on the ground. The lens broke in the same manner that you described for your incident. Canon repair in Canada was able to fix it. The camera itself was fine. So now we both have more things to double check: Quick release levers on tripods, and closure locks on camera bags .
Wow, you got lucky also. I've been looking at new ball heads, ones that have a screw type closure, so hopefully that won't happen again. Thanks for reading and your story!
Trent
EOS R5 with RF 24-105mm f/4L IS USM lens, EF 70-200mm f/2.8L IS II USM, Extender EF 2x III, RF 50mm f/1.8 STM, RF 35mm f/1.8 Macro IS STM, RF 16mm F2.8 STM, GORUCK GR-1 with TrekPak insert