Section 7 AVG provides for abstention by the administrative official and for arranging representation. It does not give a party an independent rejection procedure identical to a civil judge challenge. The facts must be brought into the administrative proceedings and, where appropriate, the appeal.
In cases of imminent danger, a biased official may carry out acts that cannot be postponed if another official cannot immediately take over. This exception concerns the urgency of the particular act. It does not remove the ground for the remaining procedural steps.
Whether a procedural error affects the decision depends on the file, the step concerned and the content of the appeal. Secure the decision, proof of service, correspondence and all records concerning the personal connection together. The later effect of a SIS alert across Schengen is a separate issue to assess.