Yes, there are conscious mistakes.  People consciously screw up all the time.  People realize that what they're doing is a mistake, but in the inertia of events, they keep on plodding forward into that mistake.  Often, by the time one realizes something is a mistake, it's too late to change course, or some other emotion overrides to keep them committed to their mistake, like pride or a need for approval. 

Example:

> Someone tries heroine and gets addicted.  They've been taught all
> their lives not to even try heroine because it's instantly addictive
> and instantly destroys peoples lives.  Yet knowing all that doesn't
> stop them.  And how often do you hear people who have been caught up
> into heroine addiction later say, "You know, I knew it was a huge
> mistake when I did it, but I went ahead and did it anyway?"

The complexity of the human condition certainly allows for a person to consciously and even avoidably make an mistake.  I don't think the term "inadvertent mistake" is at all redundant, not innately.