To be fair, I actually had a 18 year old F3 ask me last week, after a steal in which I banged out R1 (kid never slid, little bit hesitant on the new rubber astroturf stuff, but I digress), "He was out because he didn't slide right".
At first, I thought he meant if the kid had sliden he might have gotten in there. I replied "Guess we'll never know...".
He replied, "No, its a rule right?"