How is arresting a diplomat not a bigger scandal?

https://en.m.wikipedia.org/wiki/Detention_of_Johan_Floderus

He is a diplomat, who took a holiday trip to Iran, so he was not officially on a diplomatic mission when he was arrested. So the normal considerations of diplomats does not apply here.

He is being held hostage in his free time, as it were.

News like these are the reason why I don’t visit authoritarian or corrupt countries. Well, that and because I’m broke.