JT didn't say the man had shoulder length hair. If she thought that she would have said so as 'shoulder length' is a common phrase which we would all use. She was trying to emphasize that the man's hair was thick right down to where it ended at his neck as opposed to being layered into the nape of his neck.
Strange that Benice as that isn't strictly true is it?
...by 11:30, 4 May, Jane gives another description, more detailed: a dark skinned man, 35-40yo, thin, 1,7m, dark,
thick shoulder length hair, linen pants of beige or gold color, a "Duffy" type though not as thick, with classic black shoes: walking quickly and carrying a child laying across his two arms in front of his chest; by his dress, he didn't look like a tourist and didn't seem like a tourist because he was so bundled up ("encasacado"?). the child appeared to be sleeping, though she only saw the legs, the feet were bare and the pyjamas looked like cotton, a light color, maybe white or pink, with a design, perhaps, though she wasn't sure, perhaps with flowers.