Doesn't anyone use lateral thinking anymore?
The dropped taser was obviously the inflight spare that the Sky Marshall had in his carry-on. The primary taser was in his front pocket.
The Sky Marshall was accidentally assigned to look after the flight on which a Labor MP just so happened to be traveling on.
The Security screening was fine, the AFP are fine and Sky Marshalls don't get arrested.
Now let's get on with discussing something more useful and relevant to the price of fish...