It was a general comment. If I recall correctly, it was aimed mostly at the ones who moves the goal post as in example below:
Ha ha, no. Don't you see that "Milk comes from cows" is an invalid argument in itself, because the facts are contradictory. Yes, milk MAY come from cows, but since it can come from other things as well, as the facts show, the conclusion, the generalisation, is false.
Then, when countered with these facts, the goal post is moved and people pretend they have taken the facts into account, even though the entire argument is flawed.
Anyway, I think you guys should read this it explains it much more thoroughly than I feel like:
http://en.wikipedia.org/wiki/Moving_the_goalpost