griffith- comfortable win to labor, page-90

"The AEC website indicates less informal votes in the by-election. I think the Greens candidate is trying to boost the Greens' standing."

An informal vote is a vote cast that is not valid, so the voter has had their name crossed off.
The low voter turnout prediction result won't be known until counting is complete, with postal and absentee votes tallied.

The Green is probably repeating the word going around the polling stations that they felt the voter turnout was low.