Does anyone remember offhand what day it was that TG heard about the girls and contacted LE? If not, I can dig around and find it myself. It seems like it was a day or two later, and that's not really something that I'd make a mental not to keep track of when it happened. If he had also ridden there on Thursday and saw 2 bikes laying on the trail then, and heard about it on Sunday, it seems totally possible that he'd "remember" it being Friday just because it would seem so likely.
Whether he actually saw bikes there or not, it does seem likely that whatever happened it was before 1:00 or the girls would probably have been home or WC would be likely to have seen them when she drove around looking.
I think it was within a day or two that it was posted on Facebook. I didn't read it, but that's what I remember.
I think that the girls rode their bikes to the lake right after being seen on the video at 12:11 (12:19 including the time error). The cyclist was at the lake at about 12:20, perhaps as late as 12:25. That gives a total of 6 minutes for the girls to get from home to the SE tip of Meyers Lake. If we knew where the cyclist saw the bikes, we would know if they are the same bikes. If he knew the colors or the difference in size, then certainly he saw the girl's bikes. If the girls got there in that time and vanished off their bikes between the two fences, then I doubt there was time to walk to the end of the double fenced area. It had to happen really fast, and he could well have ridden by while the girls were nearby, but unable to call for help.