I agree that wasn't the best choice of language, but I think it was written that way to get your attention. THe head cushion thing may catch a few people out potentially.
however with any enforcement of any rule be it safety or performance, it's YOUR responsibility to comply and make sure you and your vehicle are within the rules, not the governing body's job to make sure.
do you even know what the rules around head cushions are? it does not take long to go and read up and check your stuff. and again if you have then you shouldnt have to worry.
most people complain when authority comes tapping on their window failing to recognize it was their own negligence that led them to their being a problem.
are you at fault if you buy a motor that turns out to be illegal? "well i bought it from a guy who raced it here so i thought it was ok"....good luck with that