I would point out that my cursory review of the document linked above
leaves a very positive impression. I don't know the actual details well
enough to know if there is any reason to doubt the document...
I would, however, tend to trust a vendor who disclosed events in this
manner. Even the best systems can fail. How a failure is handled is
in many ways the more important factor; being transparent about it is
good for confidence.
Best to plan for the occasional issue.