Conversation so far:
What is Fitzroy as related to Robert Walls?
After he retired as a player, Robert Walls immediately took over as coach of Fitzroy, an Australian rules football club
What year did Robert Walls begin coaching Fitzroy?
Robert Walls began coaching Fitzroy in 1981
Until when did Robert Walls remain coaching Fitzroy?
Robert Walls remained coach of Fitzroy until 1985
What league is Fitzroy part of?
Fitzroy is a part of the Victorian Football League
What was Robert Walls' Fitzroy record in 1980?
Robert Walls announced his retirement shortly after the incident having played 41 games and kicked 77 goals for Fitzroy, taking his overall VFL tally to 259 games and 444 goals.
Did Fitzroy's record improve during Robert Walls' tenure as coach?
With a major clean-out of older players who were clearly past it in the club's disappointing 1980 season, Robert Walls lifted the Lions to their best era since 1944.

Question: Why did Walls stop working for the Fitzroy club?
Self-contained rewrite: Why did Robert Walls stop working for the Fitzroy club?