- antecedent - all circumstances (historical and contemporary) that led to a certain behavior
You certainly should speak to the person about the incident, and let him know that it made the targetcustomer uncomfortable. You can also try to change behavior by applying a negative consequence, but behavior change due to positive consequence is much longer-lasting.
Consider ways wherein you can reward appropriate/helpful customer interaction. Positive rewards for desired behavior will help with long-lasting behavior change because the positive experience becomes a pleasant part of the persons history (antecedent) that they (consciously or subconsciously) want again. Some companies use customer surveys for this.