Forgot to mention earlier, I agree that because of what is available on the web almost in real time these days, you do have to choose your words carefully, absolutely. It is not lying to be vague in a general mass audience announcement, especially if there were good reasons to do so, however to avoid giving the impression of such, especially in the current climate, the words chosen do have to convey a sense of being reasonably specific. Exactly where this balance is may depend on the exact circumstance however I do agree that the term "operational incident" is best avoided. As I mentioned earlier, people interested in specific details can always dig around for them or ask staff and those not interested or would rather avoid can do so too.
I do also think more work could be done to explain to the general public where such announcements need to be vague and the reasons behind them as part of a wider educational programme. I think some people pointed out earlier that the public appreciate the difficulties with these things sometimes and would mostly be understanding if treated frankly and as intelligent beings, so communication about the reasons why things like these are done in specific ways plays a very important role imo in rebuilding that trust.