There's a [dead] comment below this complaining about the term 'extrajudicial'. The thing is that 'extrajudicial' means 'without benefit of legal process'. We don't really know what process might or might not have been followed had Snowden been captured. Given that forcing the plane down was both highly irregular and against treaties, however, it's hard to make a case that compliance with such things was seen as mandatory. But yes, to be fair, we don't actually know, we simply have evidence that points a certain direction.