The deal did wind up not working out, but it was a worthwhile gamble given thst it was only one year and not an outrageous price for a declining pitcher given the contracts given to other free agent pitchers at the time like Yovanni Gallardo and Mike Pelfrey, both of whom signed multi year deals.
Given that $13mill want really elite pitcher money at the time, I would just as well assume only take the risk on the one year deal in that case, rather than saddle the team with a declining pitcher for multiple seasons....