While Form 4684 is used to report thefts, individual taxpayers can longer deduct casualty losses unless they are related to federally declared disasters. This is why it was not recommended for you. It will not result in a deduction on your tax return.
The best course of action is a corrected Form W-2, in which case the correct amount of income received is what is reported and taxed.
Note the "Reminders" in the Form 2019 instructions, found here: IRS Form 4684 Instructions.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
