Hasn't pooh and the gang met a heffalump before?

I was watching the dvd with my daughter and because of the fast play thing they go right to the behind the scenes thing and the one lady says that because the characters never saw a heffalump they had to create the drawings from scratch as to what they would think a heffalump looks like. I remembered an episode of "New Adventures of WInnie the Pooh" from when I was younger in which they encountered both heffalumps and woozles (Ep 7: The Piglet who would be king, Ep 9: The Great Honey Pot Robbery) If this is so then why would they say none of the characters met a heffalump when in the latter roo even chases away a heffalump because the heffalump (Hef by name according to tv.com) so why are they so different looking and also why would she make a stupid claim like that if she works for disney?