Problem of red from 5D II (photo included)

I encountered this problem before and I just took a photo today getting this problem, thinking it should be the time I ask about it:
This is the original photo from Lightroom 4:

I use the Adobe Standard as the camera calibration, leaving everything untouched. e.g. linear tone curve, all zero setting, white balance as Daylight.
And then I did some editing:

I changed it to Camera Standard. The red flowers start to loose detail. Just a piece of Red thing. And then I change the tone curve to medium, further enhanced the effect. I changed the exposure to -0.33 and saturation to 13. And this is the final result I get here.
So most of the red become detailess, just a piece of red with the same redness.

So, my question is what's wrong with it? Is the source of problem from my monitor's gamut or is it from the camera?

How should I work with it? If it is the monitor's problem, what workflow should I use to work with something I can't see from the monitor? Thanks.