Key legal question
Whether the public law appeal was admissible against an international administrative assistance decision, including the recusal ruling on the same file.
Extracted holding
The appeal was inadmissible because Art. 83(h) BGG excludes public law appeals in international administrative assistance matters, including incidental procedural rulings under the principle of unity of proceedings.
Extracted reasoning
The exclusion ground covers both the merits and procedural issues; a separately challenged incidental decision does not escape Art. 83(h) BGG.