Oxygen regulators, medical type

This reminds me of a BG-12 owner I knew a while back. He cut a 12 X 12 " hole in the aft fuselage, so he could inspect and lube things in there. Fitted his custom hatch with a couple of hinges and a little sliding latch. Several pilots tried to tell him he had drastically weakened the structure, because the skin was most of the structure.
He wouldn't hear a word of it.
About 6 months later, he didn't return after the days flying. Search plane found the wreckage near Strawberry strip. We couldn't tell if the boom broke in flight or during what looked like a cart-wheel maneuver, but the fuselage broke right through his little hatch!
I figure 2% will never get the word,
JJ