Conditions were clean and flat - it was just a poor fishing day it seems.
Kahawai are pelagic fish. They roam all over the place, sometimes there are plenty there, sometimes none.
Some may suggest 'time of day' (8am-2,30pm) as an issue, but I would note that even in the last 10 Pania Twilight competitions there have only been a handful of fish caught total, from 20 or so rods fishing 6-9pm over ten evenings.