Overhearing Anti-Semitic Hate Speech

I recently had a scary experience. I got a flat tire and stopped at the first tire shop I could find to get it fixed. I was in a rural area, far from any Jewish population. I was the only customer there at the time. Two men who appeared in their forties were working there.
As they were changing my tire, the men were having a lively conversation in which they were saying some vicious antisemitic things. They sounded so hateful in the way they were talking. They were describing conspiracies blaming Jews for problems in this world.
I wasn’t dressed in a manner that screamed Jew. I had on a polo shirt, jeans, and a baseball cap. And I do not have an identifiably Jewish name or look. They had no clue that I, a Jew, was in their presence as they were mouthing away. I was relieved to have my tire changed and be out of that place, hopefully never to go near there again. My one regret was not secretly videotaping it to show others and expose them.
I truly believe that one who behaves like this cannot sincerely apologize for their feelings or actions. They can only feel sorry for the consequences they might face if caught.
What is the appropriate way to act when faced with this predicament? Should one stay safe and keep quiet and hope to not get noticed? Or be brave and speak up about being Jewish and confront them? I wanted to be safe and I chose the first option.