it mistakes probability for certainty. it relies on an inappropriate authority. it makes a hasty generalization. it uses a term unclearly.
Michael hit a pedestrian, Meredith, with his car, and as a result, Meredith broke her hip in three places. Obviously, Michael is the cause of Meredith' s injury. In cases of a broken hip, 100 percent of people make a full recovery, as long as the injured party is younger than sixty. Meredith is 52 years old. Thus, Meredith will make a full recovery. Michael' s friend, Jim, a widget salesman, told Michael not to settle since Jim believes that Meredith was negligently crossing the street. Thus, Michael has chosen to fight Meredith in a protracted legal battle.
The argument above is most vulnerable to criticism on the grounds that: