Hard to say--there is a map posted there but since I was primarily West Coast I can't say anything, having never done a port visit to Plymouth.
But I do know that in places like Pearl you did have time to get everyone out before clearing Papa Hotel. In San Diego, you didn't.
Well, being a Guam sailor, I can tell you that we had everyone belowdecks (bridge being the exception) way before we hit the breakwater, and that transit from peirside to breakwater doesn't take long at all. I don't understand why they wouldn't have just putted along and pulled everyone in prior to leaving the harbor...unless the CO was in a major hurry. That is the only way I can see them leaving people topside, even though there is no reason to do that.