I can see where it would be a problem, especially here. But I think the prosecution either should not have brought the 1st degree charge, or made a better case to the jury why getting the gun out of the glove box made the crime premeditated. If you are going to bring 1st degree charges against someone, it should be because you believe that's what you can prove, not because you are just covering all the bases.
Yeah, they should definitely bring the charge they think they can prove. Politics figures into these high-profile cases, and the prosecutors and DAs are subject to it. I imagine the pressure was on to bring the first degree charge given the facts. I think first degree was provable here, but once the deliberations started dragging on I figured that one was lost. I still thought the jury would likely come back with murder 2.