No. Your employer cannot legally make such a deduction from your wages if, by reason of mistake or accident a cash shortage, breakage, or loss of company property/equipment occurs.
California courts have held that losses occurring without any fault on the part of the employee or that are merely the result of simple negligence are inevitable in almost any business operation and thus, the employer must bear such losses as a cost of doing business.
There is an exception contained in the Industrial Welfare Commission Wage Orders that purports to provide the employer the right to deduct from an employee’s wages for any cash shortage, breakage or loss of equipment if the employer can show that the shortage, breakage or loss is caused by a "dishonest or willful act" or by the employee’s "gross negligence". In other words, a deduction may be legal if the employer proves that the loss resulted from the employee’s dishonesty, willfulness, or grossly negligent act.
California Labor Code Section 224 clearly prohibits any deduction from an employee’s wages which is not either authorized by the employee in writing or permitted by law, and any employer who resorts to self-help does so at its own risk as an objective test is applied to determine whether the loss was due to dishonesty, willfulness, or a grossly negligent act.
If your employer makes such a deduction and it is later determined that you were not guilty of a dishonest or willful act, or grossly negligent, you would be entitled to recover the amount of the wages withheld. Additionally, if you no longer work for the employer who made the deduction and it’s decided that the deduction was wrongful, you may also be able to recover the waiting time penalty pursuant to Labor Code Section 203.
Generally speaking, wages cannot be reduced for damages caused by improper performance. If there was a deduction you may have various claims against your employer.