We trust experts like police and surgeons to do certain dangerous tasks because their expertise offsets much of the risk; however, they're still more likely to

We trust experts like police and surgeons to do certain dangerous tasks because their expertise offsets much of the risk; however, they're still more likely to make a mistake since they have to roll the dice more frequently. And therefore the consequences should be significantly lessened for them relative to an untrained civilian? The approach you advocate will result in the perverse incentive that a cop is better off always pulling a gun in any situation, as the lack of consequences means the incentive is to always minimize personal risk in an encounter in the short term, as there's no risk as a result of a mistake in the long term. It's perverse. In effect you place the power of life in death in the hands of a trusted individual, and then create a situation where they're incentivized to use it, especially in situations where even a whiff of short-term personal risk is perceived (like, say, in an encounter with a person in a minority where racial biases may come into play).