First of all the prosecution never claimed it was wilful, deliberate and premeditated which is the definition of first degree murder. They claimed it was second degree murder because the act of firing a gun on a crowded pier is an act inherently dangerous to life evincing an “abandoned and malignant heart”, ie second degree malice for murder.
Their murder theory was exactly right. They also allowed a manslaughter charge which is a lesser charge than murder. Both theories were correct. There is no evidence of a desire to let this defendant off. The defense argued that the gun went off accidentally not on purpose. That is the fact that jury bought.
Why wasn’t negligent homicide offered as a possibility then, covering the “accident” scenario?