It wasn't there
My understanding is that it the arrival (JST620 AV-SY) diverted in Canberra around 7pm after delays for Sydney were too high due to storms; then they didn't get on the ground at Sydney (JST7620) again until close to 11pm; not enough time before the curfew to affect a turnaround before the curfew applied.
No big deal, but probably not well handled or communicated by the sounds of it.