Hey dude it happens. Let some people think what they will. The last time I tried to tell a dude, a neighbor of mine, how to install paddles he didn't believe me, big whoop right? Well he got them wrong and when he pulled up to our camp site at the sand I shamed him horribly! I was 16 at the time and he was ~40, he only made that mistake once.
It was actually pretty funny, he remarked how well they hooked up. So I said well, imagine if they were on forwards how much better it would be. Everyone there had sand experience and knew they were wrong, so he was laughed at by men, women and children.
Let the man make his mistakes, only then will a lesson be learned.