Nothing is particularly cheap at the moment in the resource...

Nothing is particularly cheap at the moment in the resource space. The ROE for a $100m acquisition (which is what they are returning) is probably looking quite low to management at the moment when you take into account the acquisition price, so they are better doing what they do best and prove up their existing tenements - they acheived 7*ROE on the CCP, so why do you doubt them?

As Oze says, they are still retaining another $100m. That is plenty to make some small acquisitions and to grow what they already have.

If you don't want the cash, buy some more stock when they give it back to you. Your return will be better than if they kept the cash and paid market prices for something worth $100m.