I suspect that Gary was exaggerating slightly when he says 75% but...
Being legal doesn't mean that you are always safe under all circumstances. A good pilot will always need to exercise judgment to operate in a way that minimizes risks. You can be legal having not flown all that much in the previous 12 months but just completed a BFR. Safe to fly a few circuts in an aircraft that has been tried and tested, sure. A first flight. Perhaps not...
Gary's caution about first flights in any aircraft is warranted, I can think of 2 fatal accidents on first flights in recent times.,the one in the Hunter recently and the one at Lismore a few years ago, the aircraft is untested and the pilot if the builder is extremely excited and nervous.