His downfall was not sticking to the original plan. It may have been ownership's call to win right away after the 2012 season, but regardless, that was the beginning of the end in hindsight. The Jays could have been sitting on Stroman, Sanchez, Norris, Syndergaard, Nicolino, etc, in the minors or just reaching the Majors, with Hutch and Alvarez already up. d'Arnaud at C, Marisnick an option at CF, Escobar at short on a cheap contract, etc.
With the AL East being as winnable as its ever been, waiting would have been the best option. Hindsight and all.