New testers

I failed a brake disc on obviously & significantly worn, one of new rfrs. A few day's later it came back with new brakes & presenter moaning about 50% left on the discs. My reasoning was if 50% left than 50% has worn away.
They were knackered & DVSA have revised brake wear criteria.

I'd suggest that as site manager you instruct him to inform you to request a second opinion from yourself on any future 'fail' discs so that you can discuss the application of his personal failure criteria regarding them and the actual current MOI and it's meaning . .

I have only seen ONE brake disc recently that I would have failed had I been testing it . It was a Connect with a 'bumpy brake pedal '. The OSF vented disc was worn through on the outer face . Was asked why I couldn't just change the pads .