If I were running a company the likes of HP I would be too embarrassed to admit I had been defrauded by an individual to tune of 3 billion pounds. Seems like really sloppy business to me.
They probably had knowledge of the problems with the company, at the very least they had suspicions IMO.
Just a guess on my part but the executives overlooked the problems so they could report the acquisition and the short-term revenue gains and report to analysts all the great things this company would do for the bottom line, stock prices go up, executives cashout then retire or leave to loot and pillage another company.
Still using my HP-15C from 1985. RPN is the only way to go.