Not every crossing is the same on purpose and due to personalities. Maybe it was just check more OK people today. If every crossing was the same then that would be an open door to moving stuff across the border.
Dog got walked, they did their job and others were passed through.
In Victoria I was waved through in the MH. DW was in the toad and grilled for 30 minutes because she had no luggage or hotel reservation or fixed destination. Never mind that she was with that MH that they just let go through - go figure.