So you got into the terminal less than 15 minutes after your scheduled time? Seems like a minor issue.
Having a Port Arrival Time (PAT) opposed to a Boarding Time does confuse people (not saying you are one of them). It is not uncommon that people think the PAT is the time you can expect to get onto the ship ---- when it is actually the time you are allowed to enter the terminal to start the check-in process.