Should I have said something when a guy at the store just now called a worker a “f&%ing idiot” because he didn’t immediately know what was in Chicken cordon bleu

So I was just at Save On Foods and waiting at the fish and meat counter. 40 year old guy with cargo shorts and a dirty t shirt comes up and asks the 17 years old looking clerk behind the counter “What's in this Cordon Bleu” pointing to the chicken in the display. The kid says “cheese I think” and heads to the back to check with the older lady that's helping me. After the kid had taken 2 steps toward the back, the guy says (in my general direction) “F***ing Idiot) So my question is “should I have said something ? Kid comes back in a little bit and says to the guy “It's chicken with ham and cheese” and they guy walked away without saying a word.