My employee slapped another employee on the arm.

An employer covered by Texas and federal anti-discrimination laws (which means an employer with at least 15 employees) has an obligation to take appropriate remedial action when it determines that an employee has been subject to a hostile work environment. While a single incident of harassing conduct would generally not create a hostile work environment, a fact-finder might reasonably conclude that a single incident involving physical assault does do so. Without dispute, if the respondent slapped the complainant's arm in anger, this would constitute workplace violence and justify severe discipline, including termination of the respondent's employment. However, if the respondent patted the complainant's arm in a joking manner, this would not constitute workplace violence. While it might justify some discipline, I am not aware of any authority that would fault an employer for not terminating the respondent's employment under these facts. Given that this incident occurred during a sales call, were there other employees present? Was the client present? Conducting a thorough investigation requires the employer interview all witnesses, including -- as awkward as it might be -- the client. Ultimately, based on information from all witnesses as well as the complainant and respondent, you should draw a reasonable conclusion and take appropriate remedial measures.