Shorted/leaky anode to ground (dag ground) was pretty common in 32" Sonys of a certain era. I am not sure exactly what happened to them, I know the Hstat block was built in but that is not likely to short, it would go open. (and they did not)

I am thinking some sort of problem with the glass or something. There is no path to ground except for the grounded aquadag. The ones I found shorted were still shorted when the CRT socket is removed, it was not an anode to cathode or whatever short, it had something to do with the dag.

Maybe a slight little blow hole in the glass, and a subsequent (after years) carbon track through there. And some of these CRTs tested good on a tester. Just the HV was a dead ****ing short.

This is because CRT testers cannot test the whole thing. There were two types, one was an emission tester and the other a beam current tester. The emission tester was cheaper and simply measured current to G1. The beam current tester which was capable of more accurate readings measured current from G2. Some of the better testers had a function to check G3 (focus electrode) leakage but none of them stuck 20 KV on the anode. It was impractical to do that.