IMO, the neighbor is not talking about his natural haircolor as a child. The word "frequently" suggests change, and gives the impression DM dyed his hair bright colors like the red in his mohawk. People tend to remember that kind of thing. Besides, as an example, I haven't seen some of my son's childhood friends in over 20 years, but I can still tell you the color of their hair.
http://www.thestar.com/news/crime/2013/05/19/tim_bosma_neighbours_miss_millards_quiet_mother.html
Yes I can remember the hair of my childrens childhood friends also... But the hair color of a neighbors son/daughter I couldn't say what their hair colors were.... especially if said son/daughter was only a visitor and didnt live with his mother. Judging by the way MB's house is situated...it would seem that someone pulling onto the driveway would only be visible to a few neighbors at best. The entrance to her home from a google viewpoint seems to recess from the driveway, so withing seconds any visitor would be out of direct view. Based on a few points like this I feel that IMO this neighbor likes to talk, and gets carried away with suggestion rather that fact.... JMO .....