For a start it would have exposed the liars.
How, in this case?
I can see how a PT-style reconstruction could rule out someone who had falsely claimed to have committed a crime (odd though it may seem, this sometimes happens, although perhaps not in PT).
I can see how a ballistics / knife stabbing, etc., could be proven or disproven via a reconstruction.
I can see how someone who claimed to be x km drive away from a crime scene could have actually taken back roads and could feasibly have been at the crime scene.
This case seems to be different.
I can't see any way of objectively reconstructing what Gerry and Jes actually heard / noticed that evening. None of the three actually agree on precisely when they were there, nor exactly where they were standing.
Kate and the curtains whooshing... as Pegasus has already found, the prints found in an opening position, according to Amaral, weren't hers and weren't on that window. In order to get curtains to whoosh, you'd have to reconstruct the precise wind conditions at that moment on that night.
SY appears to have taken the coming-and-going of various parents and has established a forensic timeline with whatever timeframes they have established. There was no need for yet another media circus at that late stage for the benefit of the PJ media.
I really don't think that Rebelo was out to set them up... I still think that he was a decent cop, trying to recuperate a mess and was a box-ticker.
On the other hand, T9/ Jes couldn't have known that.
- It wouldn't have helped the search for Madeleine;
- It would have been yet more of a media circus;
- By that time, I doubt that any of them were unaware of the so-called Cipriano "reconstruction", which took place in somewhat dubious circumstances, and for which there was absolutely no forensic back-up, but which landed both of them in jail for a very long time.