I'd be wary right there. Anyone who singled out Chapman's game for blame in the Qualifying Final is either very biased, or wasn't paying attention. For one thing he was the sub, yet had 11 disposals, 3 marks and laid 5 tackles. That was in 44% game time. Josh Caddy had 84% game time, yet had 9 touches, 1 mark and 0 tackles. Nathan Vardy had 78% game time, but had 8 touches, 4 marks, 1 goal, 1 tackle and 6 hitouts (and he was meant to be a ruckman). Blicavs, Walker, Lonergan and Varcoe were others that all had underwhelming games to put it mildly.
I agree that's why I think he had a falling out.