Hmm, that's odd. A few years ago, Australia didn't even check ID.
If you had a ticket, regardless of the name on it, you could walk into the airport, go to the gate, and get on a flight. It's a different situation, but things were generally pretty casual, and I just don't recall there being anything dramatic about a simple gate mixup.
But when you get off the plane in Tassie there's the k-9 search...
Also, it wouldn’t be uncommon to joke around (although there are some hard-asses); if they legitimately did recognise a YouTube, I could see them getting a selfie together.