"Your response was you would not be impartial because you were under duress ... and you could not deliver a fair decision," Judge Dawson said.
On Wednesday, the judge stood McAllister aside and tried to get another juror, but by that stage the jury pool had been sent home and he was forced to adjourn the trial for the day.
The trial began yesterday after a 12th juror was selected and McAllister was sent to the cells for the day, despite telling the judge he would now be able to sit on the jury.
Defence lawyer David Jones, QC, said McAllister attended court for jury service on Monday and Tuesday but was not selected.
Court staff told him there were no trials on Wednesday so he made no alternative arrangements for his demanding work schedule, including a site visit where a "near-miss" had taken place the week before.
Mr Jones said McAllister declined to hear the trial on Wednesday because the work pressures would have made him go along with what everyone else said.
"It was not a question of trying to play the system or antagonising the court - he was simply trying to be honest."
Judge Dawson said he found McAllister had been in contempt of court twice - once for refusing to take the oath and then for offering to sit on the trial.
"Not withstanding the explanation given by Mr Jones - the details of which you did not tell me yesterday - I'm still of the view that you failed to serve your civic duty."
He said McAllister had deliberately tried to avoid jury service because he wanted to be at work.
The maximum fine for failing to turn up to court under the Juries Act is $1000. It has been imposed only once.
But Judge Dawson said that did not reflect the cost to the taxpayer of losing a court day, and imposing a fine would have allowed McAllister to achieve what he had set out to do.
Instead, the judge sentenced him under the Criminal Procedures Act to 10 days in prison.
Mr Jones said he would file an appeal in the High Court today and Judge Dawson agreed to allow McAllister out on bail while that happened.
Outside court, McAllister's wife, Dr Agata Errera, said her husband had been punished for his honesty.
"I feel he's being made an example of, as the judge is trying to encourage people to be jurors ... The fact is people have excuses and complicated things going on in their lives."
She said the couple had only recently returned from overseas to find the jury summons in the post, and had little time to make arrangements.
OATH/AFFIRMATION TAKEN BY MEMBERS OF A JURY
"Do each of you swear by Almighty God (or solemnly, sincerely and truly declare and affirm) that you will try the case before you to the best of your ability and give your verdict according to the evidence?"
JURY MEMBERS IN TROUBLE
A juror in Britain was jailed for six months last year after she found out a defendant in a criminal trial had previously been charged with rape.
A murder trial in Napier was aborted in 2010 after it was found that members of the jury had been doing their own research. One juror had undertaken research on the internet, edited his findings and printed copies, which he planned to distribute to other jurors.
