Before you click on this link to an article written by Sully, here a few words from a guy who sees this all the time. Fortunately for me, lives were not at stake.
The pressure to push products onto the market is common. Cutting corners happens all the time. Then there are the internal turf wars that do nothing but increase costs.
I suspect there is a little of both of these in this case, though Sully says the FAA is underfunded. I say a little diligence on both sides would have prevented this.