Junior events race officers

Spot on! If you don't have a course diagram, simply follow App L 8.1 & refer to ...in which marks are to be passed...

If the Race Officer gets it wrong, there will still be an argument & confusion as per the original post. The solution is to write to the class and/or club to point out the error so that corrective action can be taken to make sure that it does not happen again.

Remember - If you do not respond & return the the club next year, you might get the same RO again, who has not learnt from his/her mistake. Hopefully John Knight has already done this