I dunno. i really get the feeling that the fishing pole comment was a way to explain why DR will be found at the lake. I doubt they had dogs tracking MR's scent at the lake. and he could have said he went there to look for DR when he noticed the fishing pole missing. he said he was out looking for DR all day Monday, so he could place himself anywhere he needs an excuse to be, saying he was looking for DR.
But *if* Dylan was there then why was his rucksack not on the shore line ?
I doubt Dylan would of fished with his bag on his back so that's why I do not believe he is there .
IMO , it make more sense to send LE on a while goose chase and hope nature takes its cause over the harsh winter months in a different location .