AFAIK the stance taken by airlines and consumer authorities in Sweden (and I believe in other countries too) is that as long as service have been carried out according to the manufacturer's instruction, any technical issue is "extra ordinary". Which is exactly what argument no5 is of this case.

Now this is naturally a ridiculous stand, but nonetheless prevailing.

In other words, it has been claimed that as long as normal service is carried out, an airline is entitled expect an airplane to work no less than 100% of every single minute of it's lifetime.

Now this judgement seems to completely overthrow such beliefs, and is great material to add to a EC 261/2004-claim. Perhaps it will be a tad easier to get quick decisions in the EU small claims procedure quoting this.