A police officer and firefighter have recently contacted my office for representation on injuries suffered in the line of duty. The officer was injured by a negligent motorist, was in the wrong place at the wrong time, and the negligence was not related to the officer's task at the moment. The firefighter was injured on a call.
There is a legal doctrine called the "Firefighter/Police Officer's Rule" that precludes recovery for injuries strictly in the line of duty. The reasoning is that these public servants assume the risk of these injuries when they enter the profession and that this is the reason that their unions negotiate their benefit packages. However, the same doctrine allows recovery if injuries result from negligence or mistakes having nothing to do with the the call.
The result is that the police officer can recover for his injuries but the firefighter cannot. You have to play your card hand smartly. See http://www.junelawyer.com/