Just a point, this type of incident can happen easier than one thinks.
I'm not saying this is what happened because I dont know but try this scenario.
Delayed flight....crew tight on duty time....usual corporate pressure...LVP's......long taxi to runway......offered runway with much shorter taxi....f/o told to get figures for new runway and insterts them( head down )....captain allows himself to get distracted looking at new sid or whatever( head down )....lines up... heads back up....see what you want to see....long concrete...Toga!
This is neither to berate the crew nor to defend them, just to highlight the importance of constant vigilance.