Now that last line sounds like an entertaining old wives' tale! When I was racing short track and went to harescrambling I certainly didn't try to slide around every corner dragging my left foot, much less try to do so when I started street riding. A racer simply does what they deem necessary to go around a corner at the rate of speed they are running, the corner being ridden, and the surface they are on. Both Gary Nixon and Ken Roberts were quite adept at separating the need to stick a foot out and slide in every corner when they were roadracing. Otherwise we could identify every former road racer and every former flat tracker as they either hung off or slid sideways around every corner at every intersection since they couldn't "just turn it on and off". Sounds like that guy was screwing with your head.