It is not bias to quote police as stating a fact as opposed to believing what members of an extended family cannot prove but state as fact. Ann Eaton was not the oracle anymore than you are. She and her father claimed you could lock the window from the outside, the police stated as far as they were concerned it was not possible. I suppose there was a 'possibility' Jeremy may have been able to do this but it was at best just a possibility.
A cop (Barlow) stated he looked at the kitchen window alone and allegedly stated he, "found nothing unusual with it". That doesn't mean Ann Eaton lied about being able to lock it from the outside. The statement doesn't indicate he did anything but look at the window (and other windows) it doesn't claim he tested their claim.
Eaton and others stated that they were together when they played with the window. There were various claims including this one from Ann Eaton where she explained the catch could be set up so that it could be maneuvered into locking from the outside:

Other statements detail the same claim which resulted with the prosecution asserting at trial and the appeal court making a finding that: "He then left the premises, one available route being to climb out of the kitchen window, banging it from the outside to drop the catch back into position and then cycled home."
Barlow simply looking at a window doesn't trump the claims of fmaily that say they examine dit and were able to tap the window to get the catch to fall. You need someone who tested the window and proved such was not possible to prove their claim impossible. You don't have that. You grossly try to twist Barlow's claims and actions but it won't work.