Counselor:
...let me ask my airplane-driver PPRuNe chaps a simple question: as this crew was taxiing this aircraft in this specific situation, what is the numerically stated probability they perceived - consciously - that their Situation Awareness had - suddenly / unexpectedly / inexplicably - degraded?
My take on the probability factor is that they were consciously aware when they hit the building, because SA was "out the window" (not literally) up until that unfortunate impact. Prior to impact, they were obviously somewhere else mentally.
From personal experience, the external lighting on a 747 is quite sufficient for the purpose of taxiing at night.