Sidney's dad is doing a job on Eli Stone that basically any one could do... Can't sing well either.
Victor Garber was on Broadway in the original productions of Deathtrap, Sweeney Todd, and Noises Off and in the original off-Broadway cast of Assassins, as well as in the 1990s revival of Damn Yankees. In 2005 he played the role of Frederic in the LA Opera's production of Sondheim's A Little Night Music. He's also played the lead in a critically-acclaimed Encores presentation of Follies. He has been nominated for four Tony awards, three of them for musicals. All of which blows your assertion that he "can't sing well" pretty much out of the water.
Dudes voice is weak.
No, it's not.