And a Swiss court decided that this was illegal and disproportionate [1]. Rule of law does not mean that nothing illegal happens in the country (that's obviously impossible to guarantee). It means illegal acts have consequences.
The agency who arrested him have been sentenced to pay him 12k$ + court fees. There is a criminal case ongoing against Della Valle, former head of Switzerland's federal police. It only started after the administrative ruling and parliamentary investigation.
Was any of the people responsible for his detention and expulsion actually face consequences? e.g.
* Accused of a criminal offense,
* Dismissed from their positions, or
* Brought up on internal disciplinary charges?
and again - not detracting from the valid description of the horrid state of affairs in the US.