It is not remotely murky.

EC 261/2004 does not apply to flights between two points outside the "community" (EU). It does apply:

1. To all flights xEU regardless of carrier, and
2. To all flights to the EU on a "community" (EU) carrier.

As OP's flight was neither, the provision is inapplicable.

For purposes of EC 261/2004 only, include to Switzerland and SR as an EU carrier, not because Switzerland is in the EU, but because it has chosen to adopt EC 261/2004.