Neighborhood doesn't matter. That merely speaks to the odds of a risk occurring, not the severity. You either find yourself in a violent situation or not. It isn't like an armed robber who happens to be in a "nice" neighborhood is going to move slower or something.What kind of neighborhood do you live in that the time it would take to drop a sack of groceries would be a factor in your survival?
Another note on dropping something. In the moment under adrenaline, you are going to be focused on survival. If the groceries are in a hand you need to fight, they'll just disappear as you take action. If they are in a hand you don't need, you might be surprised to see them still there and feel like an idiot "why didn't I drop them?" Because you started to draw (or strike) with the other hand, and handled the situation. Your mind wasn't diverting attention to something unimportant like what was held in the other hand.