Addressed earlier: The airline couldn't get family and bags off, do whatever else needed doing (?fuel top up?) and get out to the runway before the night curfew kicked in at 0030 local.
FWIW the flight is still visible on flightradar replay..
Looks like they departed maybe 30 min late off the gate.
When they got going it looks like a slow (by short haul standards) taxi out which makes me wonder if things were kicking off in the cabin right from the get go.
Then maybe 10 minutes stationary at the holding point (just short of where the taxiway joins the runway)...so fair bet that's where things were really kicking off and decisions were being made.
Aircraft then returns to the terminal.