Here is a thought I had.
Grandma OK'd a bike ride at 11:30, so the girls set off for a ride around the nature trail. Perhaps they see the jetty gate open and decide to check it out. Elizabeth sets down her purse inside the fence. They then leave the area and go back and are seen on the video and by Grandma at 12:15. IMO 45 minutes is plenty time for two young girls to make that trip. When they get back Elizabeth realizes she left her purse, so this time they take a different way and are seen by the man watering his grass. They get to the place where they left it and this time set the bikes on the side. But before they are able to get the purse they are confronted by a person that either looks familiar or looks like an authority figure. The person tells them that they are in trouble for being gone for so long and need to get back immediately. Lyric being in recent trouble for being out too long complies, Elizabeth sees no reason not to believe. The person tells them to leave their bikes and someone will come along later to pick them up, because they need to go now. The person leads them through a "short-cut" via that trail through the under brush.
Now I believe that the biker saw the bikes but don't believe the time he gave. He said he made a phone call at 12:27 so that only tells us that he saw the bikes before that time. He said that he called his daughter for an unrelated reason. So assuming there was no hurry to his phone call perhaps the time that he saw the bikes to the time he made the phone call was longer apart. People are notorious for not being able to identify how long something takes to do. I cannot find the article but didn't the man state that he used the rest room before making the call? So assuming it took him 5-10 minutes to get to the rest room and 5-10 minutes to use the rest room and maybe he didn't call right away so lets give another 5-10 minutes to initiate the call. That would give 15 to 30 minutes after he saw the bikes which would make the sighting on the trail to be from 11:57am to 12:12pm.
Thank you for listening to my ramblings. Everything above is based on nothing but my thoughts based on the various times provided.
This is my first post, but I have read all the threads. I live in MN and have been on the look out for these girls.
One last question, Olli did you happen to look up or take any photos looking up the trees, could there be a tree stand, or evidence of one just being taken down near the energy drink photoed location?