"And that they did not do," she said.
The woman said she didn't believe Bain should get compensation "on the balance of probabilities".
David Bain was convicted of murdering his mother Margaret and father Robin, his sisters Laniet and Arawa and his brother Stephen, at their Dunedin home in 1994.
He served 13 years in jail until an appeal to the Privy Council lead to his acquittal in 2009.
The woman approached TVNZ with her story.
Asked whether she was happy to have her message heard, despite the legal complications of speaking out, the woman said: "I have to. I have been living with this for the last three and a half years."
The woman alleged that some of the other jurors broke the rule of sanctity by bringing outside material about the case into the jury room.
Three other jurors also went to Dunedin "of their own volition" to visit the Every St crime scene, she said.
Auckland University's associate professor of law Bill Hodge, whom the woman sought for advice, told Sunday that the allegations were serious.
"I haven't seen anything as significant in 40 years of looking at juries in New Zealand.
"In most trials, a visit to the scene is something that should be controlled and visits are unruly and possibly a form of misconduct."
Bringing extraneous material into the jury room is a matter of great concern as jurors must base their decisions only on what they hear in court, he said.
* Watch TVNZ Sunday's interview here.