Brier didn't have mullets as it was, at the time, the newest housing stock in S. Snohomish County and exclusively zoned single-family. Not many poors.
Mountlake Terrace and Lynnwood cornered the market on them back in the day. Nothing close to 80's Kent or Auburn, but for Snohomish County they were impressive.
I drove through the Alderwood shopping area a month back and things have changed dramatically in that area since we moved away.
My cousin spent the summer of 1990 with my family and had a friend who lived in Lynnhood. Her hair was to the sky. It was definitely still the era of big hair and mullets.
Forgive me here on my shitty Brier takes. One of my best frens and teammates at UW grew up on the top of a hill in Lake Forest Park and he's the one who would always till me Brier was hillbillies.
Compared to Lake Forest Park, yes, Brier was definitely hillbilly. I think I know exactly where your fren grew up. I used to bike that area - park with tennis courts, hoops, etc. Totally off the beaten path from all but the locals.