My son's face was cut during c-section. The doctor said it is within the risks of the procedure. Isn't this malpractice?

It. It might be helpful to direct this question to the avvo legal site. This would give lawyers an opportunity to address this question. I hope you so is ok.
Depends. Baby is pushed up close to the fetal membranes and you can't see through them. If the doc took his/her time to gradually open the membranes with a shallow cut, babies are sometimes just beneath and a shallow wound can be produced. If he/she aggressively sliced through & a deep cut happened, it could be considered reckless. Evaluation by a legal team would then be reasonable. Shallow-not really.
Needs expert eval.. There are many risks inherent in all procedures. Whether one particular outcome is is considered to be within the "risks of the procedure" need to be evaluated by a physician considered as an expert in that particular field. You may want to consult a malpractice attorney, who if he feels the results warrantit, will have the case evaluated by an expert in the particular field.