I finally got around to taking a further look at the hull-to-deck joint. I can't really tell why it failed but my best guess is the lack of sealant/joint compound. I don't see any evidence of it in the failed portion of the joint.
Here is where the joint looks normal. That sealant appears to be from the factory.
I took some of the repair sealant out and cleaned up what I could, I am hoping I can simply cinch back into place.
A different angle and a better look at just how far it has separated.
Another angle looking down on the hull-to-deck joint.
So as of right now the plan is to strip off all the old wooden toe rails, genoa tracks, and anything else that is attached to the toe rail. After that I will repair the lifted part and fiberglass the entire joint all the way around the boat. That is the plan for now.