This was where my thoughts ended up. I was a Surface Warfare qualified officer and spent a lot of time as OOD underway on small boys in that area.
Every ship I ever served on has a notebook on the bridge called the Captain's Night Order book. He writes it out longhand every night even though most of it is repetitive. Every oncoming OOD and JOOD reads it before assuming the watch. One of the sections contains conditions when the CO is to be awakened and informed. A common one if if the wind shifts more than 45 degrees. One of those conditions is always there and concerns a vessel with a CPA (Closest Point of Approach) of 1000 yards or less.
It pains me to say this but the fact that the captain was asleep when his ship was hit leads me to suspect that the ultimate cause of this horrible accident was negligent watch standing. In this type of collision at night it almost always is.
People tend to discount the human nature element of a junior officer who doesn’t want to bother his superior officer, even though he may have standing orders to do so.
Look at what happened to Halsey in the Battle of Leyte Gulf, where his handlers did him a disservice by refusing to wake him.
Happens all the time. But with a bad outcome, usually not more than once per person!
If the CO was not on the bridge at the time of the collision, then I agree that the cause is almost certainly a negligent watch.
It's awful to cast blame, but an investigation will no doubt confirm your suspicions.
Of course, the CO is ultimately responsible, and he will be relieved if he hasn't already.