This happened to mine too and made a comment earlier on the cause and on the fix. The problem seems to be that the two bolts at the front of the engine hatch (in which the canopy latch is located ) can compress the ply plates under them and allow the hatch to lift. This in turn allows the canopy to lift and pull out the retaining pin. The fix is twofold: ensure that the two socket head bolts capture the fuselage edge firmly when replacing the engine hatch AND ensuring there is no longitudonal motion of the canopy. I placed a piece of poly ply on the rear face of the canopy frame to ensure it fits up snugly to the engine hatch and the hatch latch engages without any lost motion or slop.

As for continuing to fly when a significant piece of the aircraft has separated, is perhaps less than a good idea, one has no idea of secondary damage (in my case there was wing skin damage, or the effect of slipstream on cables etc inside the fuselage ! !

Regards, David Gladwin.