my understanding at the time was that this guy had aeroed it, overstressed it and it had failed structurally
I had not heard about that one. I would suggest that it is somewhat beyond the scope of a simple over-stressing structural failure though. Tail not airworthy to begin with, then comes off, then resulting loss of control and overstressing failed the outer wing in negative G. That is not a maneuver that a pilot could accidentally do to a whole plane!
The tails of the earlier C 150's were a little less robust than the later ones. When the Aerobat was designed, a doubler was added in the tail attachment, which later became standard on 150M's and all 152's. Inspection for this defect is very easy, and it takes a long time to go from perfect contition to "falling off", so there are many preflight and full maintenance inspection opportunities to discover and repair it before it becomes unsafe.
In any case, the preflight inspection of a C150/152 H stab should include a good look at the area where the leading edge of the H stab attaches the the fuselage. Any black stains (fretting), popped rivets, evidence of anything moving, or (obviously) cracks is cause to request a maintenance inspection before you fly it. This damage is not usually caused by flight loads, but pilots carelessly pushing down on the tail to ground handle the aircraft.
The H stab of a 150/152 (or any aircraft) is designed to transmit enough force to lift the nose off the ground - when the force is applied
symmetrically along both sides of the entire H stab, not concentrated at one point half way out! If you must push the tail down on a 150/152, there is only one way: One palm on the line of leading edge H stab rivets, as close to the fuselage as you can manage, and the other palm on the fuselage just at the front of the fairing which covers the joint between the V and H stabs. Apply pressing force there equally. If you have decided to apply a force to the tip of the H stab to satisfy yourself that it is still attached to the fuselage, apply no more than required to very gently "oil can" the top H stab skin. This force should be applied as close as possible to the elevator hinge. You may find that the owner/maintainer of the aircraft is not happy having "just anyone" doing this, so handle the aircraft in the manner they specify to you.
As has been said, the thickness of metal used in the structure of light aircraft is often that required for the minimum
stiffness needed for that part of the aircraft, not the required strength. So sometimes they are a lot stronger than required, just to be stiff enough. That introduces ironically a whole other problem for the designer, of structure too stiff, causing adjecent strucutre to endure undesired loads, but that's a whole different story!