Former Reserve Bank of Australia deputy governor Guy Debelle’s decision to stand down from his role as chief financial officer at Fortescue Future Industries is a heavy blow to FFI’s market credibility.

Fund managers and analysts have every reason to grill Fortescue founder Andrew Forrest about the heavy turnover of talented people at the iron ore business, Fortescue Metals Group, and FFI, the world’s largest and most generously funded hydrogen energy start-up.