In the movie Troy can you tell me when did Paris betray his country?

Some guy on youtube said Paris was known as an traded but and end up
winning in the long run. Skip to 0:55 to 1:43
http://www.youtube.com/watch?v=otVR8mUF5OA

I watched Helen of Troy same story but Paris didn't betray his country
in that one. I didn't watch Troy yet. which movie is more accurate?
Did Paris betray in that movie?