He got away with paying for players at LSU. Supposedly he was paranoid about an investigation at LSU so he turned down guaranteed $6 million for 3 years to stay at LSU and jumped ship to Texas A&M for $1.4 Million per year.
Sumlin was a straight shooter at A&M, so Chavis couldn't really do his thing. But I would expect Chavis to flourish with Jimbo.