I believe it was in "Outliers" Malcolm Gladwell claimed that airplane accidents are often the cause of several critical failures, not just one. It would be interesting to find out if that theory holds true in this case, as you seem to be hypothesizing.
Any kind of accident, not just airline accidents are usually the result of more than one failure.
Even simple accidents are usually remarkably complex to piece together and almost always start with a very simple small thing that by itself would not be enough to cause an accident. The follow-up to that first thing is just as important, or possibly even more so.
