Before October 1973, Israeli military intelligence worked from a fixed frame: Egypt would not attack without the air capability to neutralize the Israeli air force, and Syria would not attack without Egypt. Tactical warnings of Egyptian preparations arrived in the first days of October and were read as consistent with exercises, because the frame had already assigned them a meaning. The subsequent commission characterized the failure as reliance on a single avenue of analysis.
Lesson
A single dominant hypothesis does not just outcompete the alternatives. It quietly assigns meaning to new evidence before the analyst gets to it. This is the failure the competing-hypotheses matrix is built to interrupt.