My husband apologised and just went off our merry way. It's not like we hit him or anything, i presumed. But my husband said that he may had hit him alil, but more like a touch or a bob.
To my observation later on, he was following us so very close at the back. I could recognise his purple car. I ask my husband if he was tailing us. Turns out, he was very close to begin with (which probably cause of the bump). And if he's really following us, just to ignore him.
He was really following us! I got scared and annoyed, and until a certain junction, he drove past us, showing us his (unclear) middle finger, and made a U-turn. Well, that went well. I guess he did want to argue, but didn't have the guts to stop us. What a weirdo.