>> I find it extraordinary that a company would choose to refuse good advice or useful information, whenever it is offered so readily. This was a talented and professionally qualified engineer with years of experience. <<
I know the feelling well... I retired (aging myself, I know) from the Post Office, from a position last year where much of the work I did, I was the only one in the office who knew what needed to be done, weekly, monthly, quarterly, annual reports, IT support, etc. I gave the boss three months notice, and waited and waited to be told who to pass 35+ years of knowledge to... Three weeks before I left, the boss, who had been there on a one year detail, returned to his permanent office two hours away, and a temporary boss came in... Another week went by... I was finally told to train one person on one small portion of my job... And I had to fit that training around her work schedule, so I ended up being able to give her about eight hours training...
Sure enough, the week after I retired, my former supervisor called me a half dozen times... the first time while I was standing in front of the ToonTown Post Office at Disneyland... One of the calls was because there was no one left in the office knew where the control box for the alarm system was located and a Postal Inspector needed access to the system.