Legal Question in Civil Litigation in California

Depends on your particular facts. By the way its really a do-over, not an appeal in the normal sense.

Yes

The "appeal" in small claims court is a new trial. All evidence must be presented again. The superior court judge will not rely on what happened in the small claims court to decide whether you are liable.

To prevail, you will likely need to convince the judge that the number quoted you was a "flat fee" as opposed to an hourly rate, or that the accountant said he would only need one hour to prepare the return, or that the preparation of the return should have taken only one hour instead of 3.5. The accountant will have to convince the court that the rate he quoted was an hourly rate, and that 3.5 hours was a reasonable amount of time to prepare your return. In the unlikely case of a "tie" in terms of proof (meaning the judge simply does not know whom to believe) then the court will decide against the plaintiff. In most cases, that means the judgment will be for the amount the defendant admits he owes but has not paid. If there is no admission of an amount owed, then a judgment is usually entered saying that the plaintiff is not entitled to anything.

Without reviewing the facts in your case, it is impossible to tell you anything about the likely result on appeal. If you concede that you owe the accountant for one hour, however, I would advise you to write and mail a check for the amount you admit you owe, so that you minimize the risk of a judgment against you for that amount.

It doesn't sound like it to me, because you state that he did the work for you. Goods and services have to be paid for.