jdj125, Thanks for the info and the model id.
jjenny, I agree, it would be hard, nigh impossible for Tiffany to dispose of the jet-ski on either land or water (and very difficult for "pirates" to do it either). If Tiffany wanted to kill David and stage it to look like "bandits" did it, she would leave the jet-ski and David's body right there where the Mexican authorities would expect to find them. The effort and risk of concealing the body and Jet-ski would only raise all kinds of questions. Further more, she would most likely claimed that: "they came towards us , started shooting, we took off, David went down, but I was scared;I kept going, I don't know if he is alive or dead" That is what people would have expected. Assuming that she isn't telling the truth, the only point I can see in claiming she went to help David while under fire (aside from making her look brave and heroic) would be so that she could claim, with certainty, that David was dead. This will become an issue if there is a Life Insurance claim.
I am also very interested what that "witness" told US law enforcement (and who he really is)
I am not "positive" this is a hoax but taken as a whole: the very strange story (with all the twists and turns), the pleasure she seems to get going on TV and talking about it, PLUS, the "coincedence that she happened to have the key to the truck and that David just happened to mention the trip to his mother that morning and, well it all smells real funny.