It's well known that the chap flying the 109G when it went in was:
a) A top man
b) a great 'stick'
c) an enormously experienced fighter/FJ pilot
d) a similarly experienced single-engined warbird and display pilot.
BUT:
"Messerschmitt 109G 10/97, 18hrs on type, one hr on type in the previous 90 days (even if it was within the previous 28 days)" doesn't strike me as being sensible, or defensible, and looks astonishingly like complacency, arrogance or a failure of sensible risk assessment.
No-one should be displaying a powerful fighter type without having undergone the equivalent to an OCU training course, and without being fully 'current' on type (suggest a minimum of 120 FH/PA).