Steers Tires- Speed rated M or N

No, Dot scamming a driver!? (sarcasm there)..
Paper work long gone, this was back in ‘98 or ‘99 at scale house in Wa. During an inspection.
Different brands, and tread patterns.
Thought at the time it was sketchy and pissed me off, but he had the gun and badge, what ya gonna do?
Ever since I just match’em up, and put other somewhere else.
The RF blowout was different episode and another reason I don’t get cheap on the steer axle.
Thought I read the reg on matching steers at one time but could have been funky company rules in the way back.