Wow, I thought programs for critical systems went through stringent testing. Was this bug not fixed earlier because they figured that the probability of it being responsible for a fatal error was low ?
In my company, the management puts a higher priority on putting all available hands on rolling out new functionality than fixing bugs, in order to try and win new contracts from potential customers. Or at least that's their excuse, in my opinion there is no such thing as a low priority bug, no matter what industry you're in.