Let's go slow. You made a contention about black of African hairs being found as major reason the PLE were looking for a black. Now I don't agree that they were looking for a black and your own cites indicate that only a very few of a much larger number of hairs even appeared to be possible black hairs. Also your cite doesn't indicate when they even looked at the hairs.
Stefanoni testified that the 5 black hairs were probably Guede's hairs. Guede has distinctively kinky African hair.
In America that entire crime scene would have been processed in just a few days. While the Italians did go back later to spray luminol, and much, much later to look for the bra-clasp, I suspect as incompetent as they were, that they found the 5 kinky black hairs in Meredith's bedroom fairly early on.
I said that the woman reporting early on that she and her date were bumped into by a black man would have had a much bigger influence on the PLE than the alleged hairs.
That woman's report at having seen an African guy running up the stairs may have indeed reinforced the cops' running theory that they were looking for an African perp, but seeing a guy running up the stairs isn't that suspicious all by itself. I bound up stairs myself just for the exercise.
The cops focused in on an African suspect for two main reasons, the black kinky hairs they found in Meredith's bedroom, and they also likely had CCTV footage of an African guy lurking around that night.
BTW - if your witness came forward promptly, and if the cops suspected Lumumba early on, then it would have been a picture of Lumumba that they had showed that couple.
They didn't confirm Guede as the perp until Nov 16th, and if they showed the woman Guede's picture later, and she said Guede wasn't the guy she saw, then other than the fluke her claim may have added to the cops' other evidence that the perp was African, her eye-witness acct is just a footnote that is meaningless.
Now of course they didn't say it wasn't Rudi until...he was caught because...they didn't know what he looked like when they came forward. It may well not have been Rudi, but you see, that doesn't matter at all. It doesn't matter because they told the police a black was running in the vicinity of the cottage at a time when the murder could have been committed.
If you feel that your couple's acct of seeing an African guy bounding up the stairs, with nothing more than that, is what caused the police to focus in on only African perps early on, then you're entitled to your opinion.
No matter your theory of routes, or your belief in what Rudi looked like or anything else, a credible witness put a black there at the time. Conveniently a witness not in your favor become unreliable unlike those that give testimony months later that are in your favor, but she reported quickly IIRC AND the time was set by when they left the restaurant.
Since your couple obviously couldn't ID either Lumumba or Guede as the guy they saw around 10:30, why are we wasting time with this?
BTW – Guede was already in the vicinity of the garden where he chucked the phones around 10:00 pm, so he couldn't be back near the cottage at 10:30 pm, unless for some reason he had doubled back?
Witness says she saw a certain type running near the site and at a possible time, then police think maybe we should look for the same type.
If the police were only looking for an African perp based ONLY upon her testimony of seeing an African guy running up stairs, then the police would have had a serious case of tunnel-vision.
Why do you reject Stefanoni's testimony that she had found 5 hairs consistent with Guede in Meredith's bedroom?
Why do you disregard the CCTV footage, of which the police had lots (from at least 3 cameras), but they only released a few frames?