For mine, the Dragons defence wasn't bad in this game. Especially in the first half, you could see the Dragons working hard to shut down the Roosters attack. Thing though was the yardage game by its forwards was mostly non-existant, they rarely bent the Roosters defensive line. This put additional pressure on both Hunt and Flannagan as it cut down their decision making time, which in many cases was not great.
In relation to Flanagan and Hunt, neither looked that keen to run the ball. As such the Roosters knew they'd pass, so they keyed more on their support players when defending. In fact when Hunt started to run the ball in the second half, the Dragons looked far more dangerous. Problem though he didn't do enough of it. As was said, it was noticeable at halftime how clean his jersey was.
For mine, in the short term, the Dragons need a really good, metre getting front rower to add to that team.
(edit - Fixed typos)