I'm sure if she'd known that every word she has ever spoken was going to be put under a microscope and dissected to the Nth degree by people like yourself - desperate to 'get something on her' - she would have explained every single move she made and every word she ever uttered in precise detail. Although of course the result would have been a set of volumes and not just one book. And sceptics would STILL have found fault.
IMO you seem to be under the impression that the only words/conversations that would be going back and forth for several hours between all the various people involved that night are those which have been recorded in the files.
This is obviously not true. We only know a tiny percentage of what was said during all those hours. To claim that if there is no mention of something - (something which turned out to be comparatively insignificant once the twins woke up the next day - and would be completely overshadowed in people's minds by Madeleine's disappearance) - means that IYO it was never mentioned is not realistic IMO.
Amazing how much mileage and innuendo that can be drummed up with the very simple words ... not ... testing ... the ... twins.
Von Aesch apparently purchased and subdued Ylenia with paint thinner and it is the known modus operandi of of Raymond Hewlett a man who boasted of being in Praia da Luz and having seen Madeleine.
Sniffing the pillow doesn't sound like a great forensic technique but is probably fine for starters ... but among the mistakes made by the Policia Judiciaria as per the thread title ... was the neglect of the crime scene.
This includes the PJ allowing particularly Madeleine's bedding to be removed by housekeeping staff and laundered. It should have been bagged and preserved for examination immediately.
So by no manner of means was their failure to test the twins their biggest mistake ... it was merely one of the many.