There is disagreement between scientists on the advantage of loss of body hair - so what?
Our ancestors were hairy - we are not. The reason why is still open to debate. Thermal regulation is a strong candidate.
In my mind it calls into question all of the topics posted on the subject of evolution
That is so intellectually dishonest it is ridiculous.
There are millions of details about the minutiae of evolution that have still to be worked out. You highlighted a very trivial one. I could have suggested far more significant examples.
Imagine a Juror who listens to days of evidence regarding the guilt of a murderer. There is DNA evidence, physical evidence, phone records, forensics, fingerprints etc etc. However witnesses disagree whether or not the man they saw running from the scene was wearing a baseball cap.
If one of the jurors wanted to throw out all of the evidence based on that detail and then you discovered the juror had failed to declare he was a friend of the accused, what would you think of him?
The evidence that every living thing evolved from a common ancestor through unguided evolution is beyond sensible debate. The ONLY reason anybody doubts it is wilful ignorance or religious bias.
Shadow - What books that present the scientific evidence for evolution have you studied?
I'm guessing the honest answer is none and that you will ignore the question as every creationist I have asked so far has done.