I need help with the following scenario:

Tommy was shopping in Save-mo-Money Grocery Store when Stewart, a store employee hired to stock the aisles and sweep, accidentally bumped Tommy's ankle with a grocery cart while performing his store duties, causing a slight bruise.A short time later, when Tommy saw Stewart again, Tommy told Stewart that he should say "Excuse me," and then people would get out of his way.Stewart then punched Tommy in the face, knocking him to the ground, and called him a "hillbilly loser."

Should the Save-mo-Money Grocery store be legally responsible for either or both of Stewart's actions regarding the bump with the cart or the punch? Explain fully.