One of my best rping experiences was smiting a king (but he was ask'in for it, read here ). The DM playing their god judges them according to their code and the deity's dogma.
WWMD (What will Miko do?); I dunno. Many PC's would charge Shojo and two handed smite. Smart pally's would detect evil first, then try to arrest him. Brilliant PC's would seek the support of usually opposed community leaders -- say the church and merchant league -- in order to call for a vote of confidence.