Ann: NZX Ongoing Disclosure Notice, page-9

I think it depends on the context of the selling really. I was a bit dubious here at first but as others point out the maths probably adds up to support the reason given for selling.

Performance rights do incur tax liabilities when performance conditions are met and they vest. I think it's reasonable for them to sell enough to cover these liabilities. After all, what would be the point of performance rights incentives if you are never allowed to sell upon vesting, and they only incur you tax liabilities. It would kind of negate the 'incentive' effect.

It's a bit different to cashing out everything at the peak (see Peter Nathan) or selling your massive sign on bonus only months after signing on (Jayne).

The trouble with the management incentive schemes is that they may incentivise performance but they disincentivise insider buying. Because why put more of your own money towards purchasing shares when you are already receiving them for doing your job well. It's unlikely to change anytime soon but that's they reason we have unfortunately seen zero insider buying in the past 4 years.