(our own comparable issue is probably Northern Ireland, and the still-outstanding litigation around Bloody Sunday and "Soldier F" etc)
If a truck driver enraged about his wife's infidelity decides to drive his truck through the motel his wife is cheating in you don't sue the trucking company (well you probably do, but they lawyer up and their lawyers spell out why it's not worth your time), you sue the driver.
The problem is that this pattern of action falls apart for agents the government because of qualified immunity. If a cop does something bad and the government says "hey, it ain't on us, we told him not to do that, heck, we even trained him to avoid getting into those situations" the plaintiff is out of luck (except for the existing narrow exception to qualified immunity). Getting rid of qualified immunity would put government employees in the same situation literally every other employee is in.