Another Weird Lawsuit

Responding to a domestic disturbance call, a Chicago police office killed two people in December, one was a 19-year-old college student, the other the student's neighbor. The neighbor was killed by accident, the student because the cop feared for his life. Now the cop is suing the student's family for $10,000,000 because the shooting of the student traumatized the officer. Doesn't being a police officer means being placed in threatening and difficult situations that could involve responding with deadly force?