Lock Every Door - Riley Sager

Straight grey hair brushes her shoulders.


One paragraph later, about the exact same woman:


She tucks a lock of hair behind her ears and gives a Mona Lisa smile [...]


Did the author mean a strand of hair? Either has this woman straight hair or her hair is wavy / curly. It can´t be both. 


Well, a man is writing a female character. Maybe I shouldn´t be suprised about this.