No motive for murder unless he decided at the time that he wanted to discharge the gun.
I do not know how well the bullet deflection was proven, It seems like they would have to find the mark on the concrete to make that scenario make sense. (I don’t know what they did, all we heard is that the bullet was not completely round.)
The reason for second degree murder would be to cover the case where the shooting was an accident, which the defense seems to claim. The fact that this did not make sense to the jury is a problem with the prosecutor. To my thinking the jury would have had to find him guilty of the lowest charge if they found there was no intent.
My guess is that this was SF and the jury agrees with the whole sanctuary city BS and therefore decided to not find him guilty of anything. I understand that they want to go back and find him not guilty of having a gun either, since he did not realize that it was a gun, just something wrapped up in a shirt.
And finally, who stole the gun and left it under the bench? A nice gun like that should have been worth several days of panhandling.
The prosecution never has to prove “motive.” It is not an element of the crime.