Did they wade through the creek or not? That has always been a puzzle to me. The only alternative would be they had to go back over the bridge and around to arrive at where they were found (highly unlikely). How could one man who definitely is not dressed for running (especially, as some speculate, he may have his pants in disarray), control two, young healthy girls. All this is just thinking out loud, but how did their clothes get in the stream and why? If they were trying to run for it, how did he catch BOTH of them? I would imagine it was no easy task for this flasher/pervert.
Another interesting item I noticed early on (even before I saw the note from the photographer relating to their clothes found in the creek), if you watch the YT video of the helicopter flyover, nearer to the end is the searchers, dressed in red wading in the creek. If you look right above where they are wading, you can see clothing in the water.
These are just some thoughts and opinions (MOO), and I have to say, Agatha Christie couldn't have written a more complicated murder mystery! May they find him/them sooner, rather than later.