Qavion,
You are quite right, the FDR and CVR are located in the Aft accesory compartment, just in front of the bulkhead.
If the fin, for one reason or another, departed the a/c first, I seriously doubt that it would have had such serious implications so fast, and it certainly wouldnīt have caused any engine to "eject" either. It sould be quite easy to determine anyway, it, the V.Stab, is attachted with 6 rather large "pins" 2 in front and 4 aft. I donīt think that it poses any difficulty to examine and establish weather or not it was propperly attached before takeoff.
On the other hand, the fuel found in Jamacia bay would indicate a large fuel leak, and taking into account the maintenance history, it might be plausible the a incorectly installed, or faulty, LP fuel filter leaked, filled up the cowlings and at one point exploded. Iīm not an expert, but I have experinced something similar on a CF6-50.
Brgds
Doc