Putting on my business hat ;when an organization is transferring or accepting large sums of money from a source which is not documented in annual reports, alarm bells start ringing. This is effectively how the Enron fraud worked; massive financial losses were hidden in the books of other companies .With the way modern oversight regulations work, the Board of Directors & executive leadership can be liable for accounting fraud like hiding expenses in undocumented companies . This would be more then sufficient motivation for the board to circle the wagons, back LaPierre and hope the heat cools off before government complaint letters get typed up.
This isn't a happy thing when its Mom and Pop Nonprofit; if the NRAs got problems with its books it would be a scandal of the decade. Depending on the nature of the "relationship" between Ackerman McQueen & the NRA , this might be a lot worse then "just" excessive executive perks. The fact the Treasurer wouldn't sign off on tax documentation is a huge red light. Depending on how this cookie crumbles, there may not be an NRA left when the dust settles.