These things lead me to believe he is:
- His makeup, such as it is, doesn't have much Klingonness to it (AFAIK, this is partly at Christopher Plummer's own request)...you can barely see his forehead ridge
- He is more sneaky and underhanded than most Klingons, who would surely consider his actions in the film to be dishonorable (if a Klingon wanted to kill the Chancellor, they'd walk up to him and make an open challenge). Is it in the Klingon nature to conspire?
- His makeup, such as it is, doesn't have much Klingonness to it (AFAIK, this is partly at Christopher Plummer's own request)...you can barely see his forehead ridge
- He is more sneaky and underhanded than most Klingons, who would surely consider his actions in the film to be dishonorable (if a Klingon wanted to kill the Chancellor, they'd walk up to him and make an open challenge). Is it in the Klingon nature to conspire?