Due to Sabu scoring the pinfall in the N2R 6-man (RVD/Sabu/Taz vs. Triple Threat), he won the #1 contendership to the ECW World title. Taz and Sabu fought for the FTW title, and after breaking Sabu's neck via Dragon Tazplex through a table propped up in the corner (to take him out of the title match due to injury), and then pulled Sabu on top of him for the 1-2-3 so that Taz was title-less (and thus Douglas couldn't duck him anymore, as Taz was the #2 contender).
I also believe that Douglas paid Taz to take Sabu out, and Taz agreed only if he would get a title shot afterwards. Douglas agreed, thinking Taz would be the FTW champion so that he wouldn't have to defend the World title against him, but Taz outsmarted him.
That's pretty much what happened. The Sabu/Taz match for the FTW belt was pretty good.