We used to teach that you keep 20 miles away form TS cells / lines since hail can be projected out of tops for some miles. From the AIM, IIRC. Con, your anecdote (50 miles) makes chills go up my spine.
A friend of mine in a T-34C, back in the 80's, got lucky as he flew in New Mexico/West Texas area on a navigation flight, FL 230 or so.
Bigger hail might have done more damage than was done.
Got peppered with hail, lots of damage to the cowlings, cracks to the canopies, had to put her down and wait for a maintenance crew to come and patch it up before it returned to home station. Could have been worse.