When you look at everyone who has contact with the offender and then narrow it down to the people who know what narrowbanding is, that pretty much points to MRA.
As far as being anonymous, it could quite possibly have been something like, "Look, I've got some information for you guys but you've got to keep my name out of it." And that may be the reason no action was taken against MRA, not even a reprimand.
I have GROL, years ago that actually meant something. If something smelled bad I fixed it, or spoke up, or unplugged it or in some cases stepped far away. Motorola and GE lobbied the FCC years ago to shift the responsibility for compliance from the manufacturers and independent radio shops directly to the licensees.
The FCC narrow-banding requirements stemmed a couple decades. Only folks with archaic radio equipment could not reband with a simple reprogram. Many Taxi and Bus companies are notoriously cheap and use equipment that is worn out, and even second hand..
I cannot picture any universe where salesmen from MRA, Motorola, Kenwood, Harris, EF Johnson etc,. did not mail flyers, make phone calls and cold call the management of this and every licensee in the country. In fact salesman were using this argument to upsell Public Safety agencies to P25 even though they were operating at 800 MHz band! There was a big upside for a radio dealer replacing this fleet.
Global's CEO REZA NASROLLAHY even went to the effort to modify their license to feign compliance. Who does that?
Unless this Taxi Company was being shunned by every two way dealer in town, maybe they were notoriously cheap non paying dirtbags, in which case they had it coming.
Some customers will not listen to advice provided by their radio experts and will ignore or fail to even obtain a second opinion where it is in their best interest.
I applaud the whistle-blower.