How do I counter-argue against ex-employer's low ball offer for his Labor Code violation?

Whether you quit or were fired does not change your entitlement to the penalty. If you were fired he owes you the penalty from the day you were fired. If you quit, he owes it from 72 hours after you quit. He only owes 30 days penalty under the Labor Code. He will also owe interest on the unpaid wages. You can hire a Labor Law attorney to represent you and seek to be awarded your attorney's fees under the Labor Code.

The response given is not intended to create, nor does it create an ongoing duty to respond to questions. The response does not form an attorney-client relationship, nor is it intended to be anything other than the educated opinion of the author. It should not be relied upon as legal advice. The response given is based upon the limited facts provided by the person asking the question. To the extent additional or different facts exist, the response might possibly change.

While your question is not entirely clear, I understand you filed a complaint with the Labor Commissioner, attended a mediation at which your former employer offerred you half the waiting time penalty, the matter was set for an administrative hearing, and you are asking how you can establish entitlement to the waiting time penalty at the administrative hearing.

Labor Code section 203 provides for a waiting time penalty against employers who wilfully fail to pay final wages due to an employee who is discharged or quits. A wilfull failure to pay occurs when the employer intentionally fails to pay wages to an employee when the wages are due. However, a good faith dispute any wages are due precludes imposition of the waiting time penalty.

A "good faith dispute" exists where the employer presents a defense which, if successful, would preclude any recovery by the employee. The fact the defense is not successful does not preclude a finding a good faith dispute existed at the time the wages were not paid. To refute the existence of a good faith dispute, you may show the defense does not apply to all the unpaid wages or the defense is unsupported by any evidence or is unreasonable or brought in bad faith.

Your question provides insufficient information to offer any more specific suggestions about how you may be able to refute the existence of a good faith dispute. The waiting time penalty applies whether you were fired or quit and accrues for up to 30 days from when the wages became due. Good luck with your claim.