When I looked up the rewards you can get from the Bounty Hunter Week event, I was elated to see that listed under the potential rewards was the Grey Helix Lightsaber. Says it right there.
http://www.swtor.com/info/in-game-events
I looked for the vendor that would sell such an item, so I would know where to go, but doesn't seem to be anywhere. Now my guild tells me that the Grey Helix weapons are only available through the Gree event, which I just missed. Just thought you should know the website listing for the BCW event is perhaps incorrect.
Jathek.