It didn’t confound the Captain. He was in his stateroom, probably asleep. The motion of the container ship confounded the Lt or Ltjg that was the OOD at the time.
One thing is for sure. The written orders from the Captain to the OODs of ship probably required them to call him if any ship was going to approach closer that a specific distance, say 2000 yards or so. This, apparently did not happen. That is the OOD’s responsibility. Why did it not happen will be a question for the OOD to answer from his end of the long green table.
“...Long Green Table...”
Yeah- that long green table.