My bash concerns;
- failure to secure cabin before 'foreign' language tape ran. People were still in the aisle and stowing/moving carry-on.
- the cabin crew were doing other things while briefing was being played.
What would I have done? Well how about exactly what EasyJet-Switzerland does. They do a full briefing in both French and English (on flights to/from Geneva - I'm not certain what they do in Basle but I suspect they do German/French/English). Swiss do it in three languages.
The crew don't need to be fluent in the 'other' language of the flight, but they could follow along demonstrating the safety items. If necessary English 'cues' could be included in the text to prompt the crew to what they should be doing. The demonstration is an important part of the briefing, and I doubt if the CAA would have a problem if a full demonstration was done in more than one language.
I am astounded that local language briefings are not done on domestic flights. What are they thinking?