Perhaps the second officer thought as you already needed to change the plates, and produce documents he might as well get you to do it as well. Means he reaches his target quicker, and no extra work for you.

Might have saved someone else getting a producer, as the officer had one less to get!

IIRC if you have a defect notice and have been given say 7 days to rectify the issue, you are actually exempt from being done for the same thing again during those 7 days, showing the officer the producer should be sufficient. Am pretty sure that was the ruling when I did my CPC but that was a few years back.