What can be done when retaliation and intimidation by an employer occurs.

My son had a situation where an employer grabbed his arm for not responding in a way they liked. He told the owner she can't touch him. Since that incident in mid December he has not been on the schedule. All others are getting hours during this period. During this time off he reported the company to the Wage and Labor board for not giving check stubs with pay checks. After the board contacted the company, one of the owners called him. She asked him why he reported them, and during the conversation made a comment about how her lawyers were very reputable and very good. Is this a case of retaliation and intimidation by an employer?