You (and the author) assume that the USN was caught flatfooted by the bold, daring gesture of the gallant PLN, to which I call bull****.
Calling it "stalking" is on the order of saying that mice "stalk" snakes. Look, the mouse walks right up next to the snake! What a daring gesture by the mouse!
The Chinese sub may have gotten close to Kittyhawk, but given her peacetime posture, it was not overly surprising.
Doing the same during war is different.