There is clearly a sports metaphor: the word passe means the action of passing the ball in football/soccer, so it makes sense to make an allusion to it when commenting a football match.

There are numerous crude jokes in French about the double-meaning of passe (which can also be an act of sexual intercourse with a prostitute), but that does not seem to be the case here.

If we follow the logic of a football metaphor, the journalist is le roi des passes because he is good at asking sharp questions that the interviewee can use to their own benefit, if they answer with a witty retort – just like a football striker will put themselves in the spotlight if they score a goal after a good assist (= passe décisive) from a team mate.

The answer “merci quand même” may seem a bit contradictory, but may just mean that the mayor acknowledges the journalist’s wit but refuses to play along.