Yeah. Supercooled water droplets can be there in a thunderstorm. Normally, that’s too cold for ice to form. In my airplane, we turn off the anti ice when it’s colder than -40c. Either way, there’s no anti ice on the Lear 60 tail, from what I understand.
I’m guessing either the turbulence over stressed the aircraft and blew off the horizontal stabilizer or the horizontal stabilizer got iced up and then the subsequent forces blew it off. It appears to be missing in the video screenshot I saw.
Either way, the NTSB will sort it out. It’s amazing what they can uncover, even with this much damage.