CAT boots, approx women's size 5 (Loughborough LE11)

My son bought these CAT boots from an online charity shop. The label in them says unisex size 8, but he can't even get them on. I usually wear a size 5 and they were quite comfortable, but I wouldn't wear them! There's also a label "Sample, not for resale", which might explain the curious size.

please advise when you can collect