A Cook County jury has awarded $742,500 to the children of a man killed by Chicago police responding to an argument at his girlfriend’s home.The jury determined that Hector Hernandez was partially at fault in the incident and reduced an initial award of $1.35 million to $742,500.Hernandez’ estate alleged that two officers used “inappropriate deadly force” and failed to de-escalate a mental-health crisis situation, among other claims.On April 7, 2014, Hernandez, 21, visited the home of his …