A man at a petrol station. (Longish)

A man was a petrol station. He fills up his car but spills some on pertol his arm as he puts the pump away. He pays and leaves. As he drives away, he lights a cigarette and his arm on fire. He frantically waves his burning arm out the window and a police officer behind him pulls over and helps him put it out.

The man thanks him profusely. The officer says, "No problem but unfortunately I'll still have to charge you."

The man asks, "charge me? What for?"

The officer replies, "unregistered firearm."