What you're saying is, "Well they didn't need to hang around because they had a defence to any charge." That's like saying, I didn't bother turning up to my murder trial because I knew I'd be acquitted with my defence of insanity.
Invoking the treaty might constitute a defence to a charge of assault, but the point is that the fact that a defence might exist does not meant that an investigation should never take place. The real question is whether the circumstances of the incident entitled them to protection of the treaty and I think that is worthy of investigation.
And moreover, if your point is that it is irrelevant whether or not they used excessive force because either way, they are protected by the treaty, I don't see how that means their conduct was vindicated and she was in the wrong. My point is not to engage in a dissection of the possible legal defences that air marshals might deploy - i am simply saying that maybe the
facts of the matter are not so black and white.
And in any event, unless you are a lawyer specialising in international law, you will forgive me if I don't just accept your interpretation of an excerpt of the Tokyo Convention - not that it's relevant to my original point anyway.
If I end up being assaulted one day by an unscrupulous air marshal, I would like to think that upon arrival back home in Australia, my complaints to my government might be heeded. It's pretty clear that I won't get much sympathy round this way tho!!!
As for the American pilots who were detained, pretty big difference I'd say!!! I assume that was in relation to the crash with the GOL plane in which 150 people were killed!! Why wouldn't they detain the pilots until the investigation concluded, particularly given that, from memory, it transpired that the US plane did not have its TCAS on at the time of the accident (it had been accidentally disengaged by the pilot as it turned out)? Respectfully, i don't think that falls into the same category as the incident we're discussing.