That sucks, Maybe they were on drugs or something? Once a random guy approached us in the street and he was really friendly, then later he walked upto my mate and punched him, then this guy was walking past and he walked upto him saying "Hey, You're my uncle from Glasglow!! Wanna have a drink?", It wasnt his uncle, it was some dude who lives up the road from me haha but yeah he was obviously on something.