I forgot to add; If it makes you feel better, the damage would probably have still occurred even if the boat been covered. The coring was wet already and given enough moisture and freeze cycles, something had to give.
Hard tops are often overlooked as far as maintenance goes and understandably since access is a pain.
You issue made me aware that I am also negligent in that yesterday I checked on one of my boats ( to readjust the cover) and as I was closing things up, I noticed a developing rust stain on the bottom edge of the hard top mounted electronics box. There is a mic bracket there and I said to myself, "I will have to clean and reseal that spot. Until today, It didn't occur to me that to stain, there has to me moisture and I probably have a leak that gets into the electronics box. Guess what the top of that box is; The hardtop with it's multitude of bolted through hardware. Guess I will add that to my spring list