Ohforsure,
In all honesty, are you, as a shareholder happy to accept an unlimted number of (unfatal) engine failures due to cheaper offshore maintanence? Will you admit that this has been a management blunder?
I'm very interested in evidence of management blunders however, I'm not convinced this is a valid example. Let's assume that the increased failure rate is due to change in maintenance rather than a statistical blip (a 95% confidence level, assuming the data is all valid, is quite compelling, but there is still a risk of a data mining bias). Now you can only judge whether the decision was reasonable based on what was known at the time. If figures were available at the time showing that Qantas historically had failure rates 1/3rd of their peers, and that the cost of the increased failures would outweigh the savings, then yes I would admit it looks like a management blunder.