Mixed Conditionals

It is possible to mix the first and the third conditional:

If she is such a good doctor, she should have diagnosed the disease.

Here, the problem that makes me doubt her ability is in the past, but my doubts are present. If I use a more certain modal verb, the sentence changes:

If she was\were such a good doctor, she would have diagnosed the disease.

Here, her failure to diagnose is clear, so I do not believe in her ability.

Most mixed conditionals are taught along the lines of starting in the third conditional (past action) and finishing with the second (present\future result:

If he hadn't broken his leg, he would be playing in the match.

However, there are more complex conditionals where past result affects the current situation.

See also: http://www.usingenglish.com/glossary/conditionals.html