If by EU court you mean the European Court of Justice, then you are correct. All rulings so far have been that technical issues are not extraordinary, but reading the rulings I feel they relate only to the specific cases, not a generic statement.
If by EU court, you mean any court in the EU (i.e. the local courts that resolve most of these cases), then I don't think it is so clear cut. A ongoing case in the UK (Hasan vs Jet2) relates to a Jet2 flight delayed by 24 hours due to technical reasons - 4 people on the flight sued the airline, and all lost. It was only when one person appealed to the county court (after hiring a specialist legal firm) that they won and the case made the news.