That's a subtle fallacy. It confused me at first, then I realised that 'pointing out hypocrisy' isn't the fallacy, it's 'claiming the argument is wrong because it's hypocritical' that's the fallacy.

edit: on further examination, the examples given in the wikipedia article are really bad - because they're merely pointing out hypocrisy ("but you're -foo-") rather than claiming the argument is wrong. Person 2 in each example could quite happily be in full agreement with the argument and make the same comment.