Yeah, I cannot really see what you mean from the screen shot. It's also tough to work out especially considering you didn't include the information I suggested to include.
What you're describing, depending on the actual effect can happen for a couple of reasons that I'm aware of.
Since (you say) you're adding red to the shadows, it can depending on what kind of adjustments you're making and how far you're pushing them.
One example is the differences between log more and primaries mode in Davinci. Log mode has more overlap than primary mode. Both have benefits and drawbacks depending on the situation. If you're in primary mode, you can make an adjustment to the shadows and there is an arbitrary spot where it'll just stop. If the light changes from frame to frame it can cause unexpected results. This doesn't happen as much in log mode unless you're pushing the wrong information too far.
Another common place is when you cause artifacts is where there is no information to recover when you're readjusting the boundaries (Eg lifting the reds in your blacks). Under exposed or over exposed footage most commonly, though it can also happen when an aggressive codec compresses your video information too far to have the information altered or recovered. When you adjust that portion of the video, it has no information to use so it extrapolates or guesses (depending on how your software reacts to this) what should be there, often guessing wrong.
I'm not sure if this is happening to you, If it is the case, you're moving into damage control instead of creative choice in your color grading process.
It'd odd though, since I don't see any red in the blacks, more in the lower end of the mids. Also note, some red seems to made it on to his face. It might be worth deciding if you want to keep it there.
