Incorrect info here - it is both the employer and employee to know the rules of engagement (employment). Under no circumstance can a WHV holder work more than 6 months for the same employer, not even can a waiver be issued for this.
Now, I'm not saying you are wrong but I have seen this happen first hand of a pilot working for 12 months or so on a WHV. So either it is a loophole or the employer had employed an employee on the went visa. Said pilot has now moved onto bigger and better things back home.
But I do agree with you and know of a few Aussie pilots waiting 12 months plus for an interview and position.