No he was not. Why do people keep saying this?
The spine of the team, and the players that actually played for us once we got back to the PL, were already at the club before he joined (And he eventually sold them all)
Most of the players he signed in the Championship were gone by the start of the 2013/14 season because they were not good enough.
We had a core group of players that went on to play at the highest levels. Champions league, world cups, European championships etc. Promotion was inevitable.