Cop Punches Mom Holding a Baby

Recently, a new sheriff was elected in Los Angeles County. He held a press conference about some bodycam footage that he had just become aware of, showing a deputy punching a mother in the face, in an attempt to take the baby from the mother over concerns that she had not properly transported the child in a carseat. Did the officer act reasonably?

By the way, this is the same agency that is also under investigation for another incident, wherein an elderly woman was slammed to the ground unnecessarily.