Hi JustJenny. It's difficult to be sure, but I think that it could also be anxiety, for example, that makes him pull his hairs and get upset for changes (I'm stressed too when I have to change phone or change a plan, but I have both OCD and anxiety and sometimes it's difficult to make a distinction).
To be diagnosed with OCD you need to have a lot of obsessions and compulsions that steal you much time...except with the pillow, do you think he has others and that they steal much time?
How donyou think he would react if you seggested him to see a therapist?