It sounds as though what you are saying @EileenGC is that the delays to vaccine deliveries to EU countries have particularly bothered people because, culturally, there is less acceptance/tolerance of delay or change in the health service in certain countries. Whereas, in the U.K., there is more willingness to accept delays/cancellations because they are more commonplace generally when interacting with the NHS etc.
I can accept that may well be the case but if we are saying that those supply issues/delays are causing similar issues in both the U.K. and EU countries and it's just the tolerance for those issues that is different then I'm not really sure where that gets us?
AZ may have over promised and under delivered (i don't think we can be sure of that as yet) but legal action will make absolutely no material difference to the practical outcome of that at all as far as I can see.
Sorry if I have misunderstood what you were saying!