I think there were many reasons for the way the defense performed.
1. The predictability of the Rams changed with Linehan calling the plays, Leonard at RB and Ferrotte at qb.
2. The Rams did get a couple of players back
3. The inevitable trap letdown.
Leonards performance will not go down as a great game. He had a couple of nice runs, but as someone said , I think the Cards were not going to let Tory Holt take over this game.
The D was getting some pressure and a were a half step away from 3 or 4 more sacks.
Although we may have not played our best game we did the little things that were neccesary to win.
Three picks( one to the house), 2-3 sacks is not bad. Also consider Leonards had 35 yds rushing in the 1st series and 67 for the rest of the game.
To put things in perspective, The Rams looked EXACTLY like the Cardinals of old. They played hard, but played just bad enough to lose.