The report only states the conclusion that the breaks did not work for the current configuration.

Which is a slightly awkwardly worded way of saying, “well obviously they didn’t work because we know they were applied and look at the result“

This is only an initial report. They still have no idea why the breaks didn’t work, and for how long they haven’t been working. Could have been a recent malfunction, something that happened during redesign, or a an inherent flaw going back to the original design.