However, if you knew there was no chance anybody elses DNA was going to be on/in her, well then you'd have to explain it right away. Afterall, they know the security guards didn't have sex with her. It's a statement that says they knew the guards didn't have sex with her.
Ok, lets look at your post. They admit to sex iwth her. They might not do that if they thought the guards might have. Thy also might admit to it if they think her body or clothing will be found with their DNA on it.
I was holding out hope that she might still be alive until I read your post.
The big question is do they have any evidence that the guards touched her in any way, or are they going to blindly accept the stories of the 3 guys, even though the 3 guys might be linked to her, where the 2 aren't?
That's my point.
They knew without saying so they she would not show up.
They also knew without saying so the guards didn't have sex with her.
The FBI will do forensics and declare the guards innocent, and then the other three will get picked up. This clears the Aruban powers-that-be from any arm-twisting.