Stealing the show

Stealing something from somebody (including a show) who would gladly give somebody something doesn't seem like an action with a lot of honor in it. Being indirect about it instead of straightforward makes somebody more of a liar than a thief.

They would've given him/her the show, as it said to do in the script, but he/she still insisted on a coup to steal the show. Stealing the show had always been his/her true intention, to get the best of any of the other guy there was.