I think your original, still unanswered, question was, "do TB's just break?".
I have zero experience with that outcome, but what I have read here for nearly 20 years, the answer is yes, they just break anecdotally when parked, most of the time.
Why, I have no idea, but am very curious. The explanations above do not address, IMO, why its most often when parked.
It might be the ones that broke at speed, put the driver in the cemetery, and we never heard the real reason why they crashed?

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.