Anchor: The way a witness presents himself affects the credibility of his testimony.
Entailed: A witness' credibility is affected by his presentation.
Contradiction: It does not matter how a witness presents himself.
Contradiction: Two goldfish are riding bikes in a giant pile of mashed potatoes.
Contradiction: A bunch of people are together
Contradiction: The kid is riding a board with wheels on the street.
Contradiction: A human riding.