The sweet guy who liked living alone & worked as an electrician. He got in the van & she said she would drive him home. We then see her alone in the van. But the guy we first saw killed was the cocky football fan with the scarf. Did she let the 1st guy go and, if so, why?
I think he said something about family waiting. She seemed to reject people who weren't totally solo.
Another thought crossed my mind, though. They built up the mystery slowly, exposing us bit by bit to what was going on. So, maybe the first guy was absorbed, but they didn't want to show it to us yet.
There were several things in this movie that were ambiguous. I liked that, though. It keeps the mental gears turning.
I thought maybe he was the guy in the null space who imploded, although it was hard to make out his features. The other possibility is that the guy who imploded was the one she took off the beach.
She didn't take ones who would be missed or whose absence would be immediately noticed due to missing an engagement, which is why she tried to find out their plans and living situation. The marks have to be attracted to her, too, and maybe she felt he wasn't interested.