Lots of time on the flight sim is one way....

The modern flight sims are almost good enough that if you are conservative about how you fly the real model... you can almost move directly from the sim to any model, never having flown any physical model before.

Pick a windless day... and ensure you have adequate airspeed at all times ... and the model will behave just like the sim. The experience with the glider got him the control reversal training in "real world" (because the reversal effect does seem a bit different in real life than on the sim)

So... yes I can see it happening. I can't see a large percentage of people getting away with it if they tried, simply because of the "pucker factor" involved with risking $300 to $2000 worth of model when you KNOW you haven't the real life experience. (there is essentially no "pucker factor" when just risking needing to hit the reset button...)