I was as far from the nest as you could get, on the road near the CSIRO gate but this bird still wasn't happy. I retreated until it finally gave up harassing me and others and retreated to the nest tree. I then ventured further down the road and watched as the second parent arrived at the nest tree. Neither entered the nest to feed the chick.
I'd been closer to the nest the previous week with no sign of either parent, with the chick sitting up in the nest and spreading its wings.