Elmo... so so so sorry to see the mess... yeah, that would lead one to have a bad day.

Is this "water" or "heat" expansion? Was it hot when you went camping? Another option might be: remove your roof vent, use a router and straight edge and dado out a grove/strip along the seam and sand back the duraback an few 5-6 inches on both sides. Fill the void with epoxy, a couple coats put on over a couple days, and feather it back into the sanded area, let it cure for 4-6 days, lightly sand w/ 80grit for some good "grip" and then reapply the duraback for a transparent fix.
If it's "water" cut out all the ply that shows evidence of moisture and "cap" with epoxy, or it will just keep seperating. I'd try this before you spend a bunch of time and money on aluminum, etc.; you have a router and you have some Duraback, maybe try just investing in a little "time" right now. You may have had just a little pin hole in the duraback or something. Did you seal the wood prior to applying the Duraback?
Man, I'm terribly sorry about the mess; I hope you get 'er fixed and can keep on enjoying.
