Very nice photo, I agree with you, it's flat, you almost made up for it with the saturation, but still, there is not enough shadow detail. It's mostly midtone. I had to open it up in photoshop because I was curious to see what the histogram looked like..
Alot of the shadow detail is cropped off the histogram. Which I think is why it looks flat. You could try to move the midtone data to the the highlight side of the histogram making the shadows darker, but you will lose some image qulaity in the final product by doing this:
Just a suggestion, It's a good idea to check your histogram after a shot like this to see if you got all of the data recorded. If not, you can always adjust your exposure and retake. Also, RAW is more forgiving than JPEG when it comes to shifting data around the histogram.