2004 and 2005
In 2004 Hawthorn won 4 games and finished 15th above us. They won 2 games in the first 8 and then lost the next 10 in a row. So what week was it in that outstanding run that they started to tank? They won 2 of their last 6 games (beating the 14th and 16th teams) and were only beaten by teams above them (by 80, 44, 17 and 65) - hardly tanking.
In 2005 they won 5 games and finished 14th above Collingwood and Carlton. They won 3 of their first 9 and then lost the next 7 in a row. So what week was it in that sterling run did they start their tank? They won 2 of their last 6 games (beating the 13th and 16th teams) and only lost to teams above them on the ladder in the other 4 (by 48, 41, 4 after kicking 13 2nd half goals, and 54) - again, hardly tanking.
In the last quarter of both seasons they lost every game they should have, against teams that should have beaten them, by margins that required no tanking. Nope, move on, no tanking here.
As I said - "no team has ever ever ever ever won a flag by tanking and it's not about to happen anytime soon".