Vogon took her over to the pool to splash around and have fun. While they were there, they noticed a single male paying an inordinate amount of attention to Laurel -- sitting on a chair in the shade with a towel over his head, looking intently at her, then turning away whenever Vogon looked at him. He got up when Laurel got out of the pool, then followed them (3-4 feet behind her, with Vogon repeatedly reminding her to stay with him and not dawdle behind) all the way to the gate before turning and going back to the pool.
After Vogon and Laurel came in, Vogon took the camera and went back by himself. He found the suspiciously-acting guy sitting in a vehicle at the exit gate trying to leave. (He wasn't at the right point to trigger the automatic opener.)
We called the police non-emergency line and reported it afterward.
No more joking about "stay with me so you don't get kidnapped by white slavers".