Auckland lawyer Peter Kiely was recount scrutineer for the National Party
and said some changes came about because votes allowed on election night might have had a mark in the box rather than a tick.
Kiely revealed 425 declared votes were disallowed - nine were dual votes, 393 ineligible votes and 12 were not authorised by a witness.
"Those 393, not only were they not on the roll in Waitakere, but they weren't enrolled anywhere."
Kiely had been involved in a number of judicial recounts for the Nats and said the potential high cost of mounting an electoral petition might put Labour off.
He said in March 2006 Winston Peters was ordered to pay Tauranga MP Bob Clarkson $40,000 in costs after a failed electoral petition.
Labour Party president Moira Coatsworth said the question of whether to pursue a petition would be discussed at a meeting on Tuesday. Sepuloni thought it an unlikely course though. "We'll see. It's a possibility. I've got to have that discussion with the party."
Despite losing the seat, she was proud to have come so close to winning.
Bennett said she had a "true Westie" party at her house on Friday night after hearing she was back as an electorate MP.
An electoral petition must be lodged within 28 days of the official results being declared on December 10.