It seems easy enough to reconcile. A good enough algorithm to excellence is the old three-phase: Do it. Do it right. Do it fast. So in this case, Move Fast

It seems easy enough to reconcile. A good enough algorithm to excellence is the old three-phase: Do it. Do it right. Do it fast. So in this case, Move Fast and Break Things means that when an aspect of the work is in phase 1, there should be evidence of things breaking so you know that progress is happening at the maximum possible speed. Then because things are moving fast, work quickly moves into phase 2 of taking the breakages and fixing them to a high standard. Although I make no claim as to how it actually worked at Facebook.