It was reported that Arians was retiring after 5 years as the Steelers OC. However, about a week after leaving the Steelers’ franchise, Arians was hired by the Indianapolis Colts for the same OC job.
The answer lies with Dan Rooney.
The team, led by Rooney, basically evicted Arians, but did not fire him. They simply forced him out of the job. They didn’t fire him, and he didn’t really retire. He was told to retire so that Rooney wouldn’t have to fire him.
Ya, it’s confusing, but I view Rooney as the ring leader.