It is a double problem with the basic war time footing that our sailors have been under since 9/11 which can put our sailors into being mind numbed robots like your nephew.
Also, that war time footing and exhaustion cuts into or eliminates the necessary seamanship training needed from the CO/XO, other officers down to the enlisted sailors on watch while the ship is underway.
The lack of good underway training and being dead tired is a deadly combination.
What could possibly explain neither ship sounding pre-collision alarms? Iirc most of the 17 who died were in their cabins, and two heros died while pulling sailors out of their smashed cabins.