I definitely do not know all there is to know about the case and the search for Dylan. However, my honest feeling about this case is that he will be found in the lake, unfortunately. I have a feeling that LE does know more than they are telling -- or at least they have suspicions as to what really happened.
I can't imagine LE thinking they were dealing with an abduction with an unknown person as the likely perp and NOT have spoken publicly about it. They would be risking other children going missing, or other clues that might have been important were it an abduction by someone local, OR out-of-town. (For instance: If, God forbid, it was a local person who did this and then another child went missing the town and police force would be opening itself up to some major lawsuits, IMO.)
I have my own personal feelings in regard to how Dylan would have gotten to the lake, but it's all just based upon my opinion and gut feelings - nothing solid to back it up with. And, let me just say this; I hope that I am completely wrong, and that Dylan is somewhere safe. That is what I continue to pray for when I think of him and his family - that and for the truth to be known, no matter what that truth is.
ETA: I just keep coming back to the fact that there were two different dogs that alerted at the lake - in the same place, IIRC. Too much of a coincidence, IMO.
Also - there was a mention of suicide. I don't think there's anything to suggest Dylan was suicidal. I think the plans with friends the next day, and his confirming those plans would contradict a suicidal mental state.