Now, this might be a case of semantics - primary navigation in this case meaning a valid chart - but on it's own, Air Navigation was not considered by the inspectors of the BR suitable for flight without a second means of navigation - ie, an actual chart.
Steve, I bet this guy was let go and there was no fine or investigation because the actual law is in favor of the Air Navigation Pro user. The law (
§ 3 3. DV Luft-BO) just says "current and suitable for the flight". This means that anything will do, as long as it is suitable and it's up to you to choose. The hurdles are pretty high for a judge to rule that your ANP is not suitable.
However, there is no way to fly with outdated maps, the above provision is very specific about that. Not even if nothing has changed!