Ex-chiro here. I saw the hit. Vertebrae don't fracture from that direction of hit, with that line of drive and level of force, into a heavy plastic and foam chest protector. Not impossible but virtually impossible. Even a subluxated or dislocated sternum would be pushing it, with a hit no harder than this was.

Also they restarted his heart on the field, so there goes the vapid "fractured vertebrae" lie.