premise: There is a street with people walking and walking their bikes, in particular one man in the forefront who have a black cowboy hat and black clothing on and a handlebar mustache. hypothesis: A man is driving on the highway.
contradiction: YOu are either driving on a street or a highway not the both of them together.  A man is one individual where as people is referring to a group.  Either you are walking bikes or driving on the highway.