Legal Question in Business Law in California

It is hard to say without more details. It is generally not a good idea to take money out of en employee's check without their prior consent. Why not suspend the employee for a day and give their shift to another employee?

In general, employees are not allowed to take money from an employee's earned wages in order to receive compensation for employee errors. The employee may be disciplined for repeated errors, or even terminated, but employer self-help for errors by taking money out of earned wages is almost certainly not permitted.

You may want to speak briefly to an employer-side labor lawyer about this issue. Errors in handling employee pay can lead to real problems.