premise: Police are investigating after a motorcyclist and his pillion rider were seriously injured in a crash near the Perth CBD last Wednesday evening. About 9.25pm, the 22-year-old man was riding a red Yamaha 125cc motorcycle north with a 17-year-old pillion passenger over the Narrows Bridge along the Mitchell Freeway. The motorcycle involved in the crash. Credit:WA Police As the motorcycle passed the Mill Point Road exit, it was hit by a silver 2005 model Honda Accord. The rider and passenger were thrown from the motorcycle and received serious injuries.
hypothesis: The pillion passenger, seriously injured in the crash, was a 17-year-old man.
reason: The article does not specify the gender of the pillion passenger.  It just refers to them as a passenger, so they could be male or female.  I'm not sure why the agent got this wrong.  They may have lumped the driver and passenger in together, or not have recognized from my sentence that an otherwise unspecified gender was being explicitly stated.