He might have done, I'm not sure. The latin words strengthen the spell and make it easier to learn the spell to begin with, but they're not essential, and can still help if they're not quite right, so you might be right. It's the principle behind non-verbal spells.
And I'm sure I heard somewhere than swine flu is technically the bird flu mutation we were worried about, it is a H5N1 strain of the virus just like bird flu. But I might be completely wrong, and it doesn't make the joke any less crap.