Get him to demonstrate his technique on a 500M runway
Preferably while you watch from the sidelines!
BUT, I have also seen various instructors around the world use 70+kn flapped approaches, causing some combination of hard landing and float
I once flew an ILS in a 172, flaps-up and full throttle, to accommodate an ATC request - they had jets turning final 50 miles out! I closed the throttle over the threshold. You wouldn't believe how far we floated before I could even lower the flaps, never mind touch down. Luckily, it was a 13,000' runway.
