Greg Olson joined the Jacksonville Jaguars staff for the second time in his 28-year career, but the second time around was under much better circumstances: a better staff, a better personnel and Olson coming in as an offensive coordinator rather than a quarterbacks coach.
Olson left in 2012 thanks to two reasons. First, he was offered the offensive coordinator job with the Oakland Raiders—an understandable reason to leave. Second, he had enough of working with QB Blaine Gabbert—an even more understandable reason to leave.
Despite the horror that Gabbert brought to the Jaguars and Olson himself, when the Jaguars offered him a chance to come back as OC, he took it.