Driveway sealing sprinkled on concrete walkway how do you remove?

I got my driveway sealed by local driveway sealers. They sprayed tar on it. It was a windy day. I noticed when they were done there was a couple sprinkles of tar on my concrete walkway nothing horrible. I wanted to remove it but the guy said if I touch it, it would smear bad. Usually when stuff happens they say attend to it immediately but not in this case? What can I do to remove these sprinkles of tar that got on my driveway? I heard gas could work is this correct? What is my best method and when should I attend to it?