"I kinda doubt that this woman "shot high" in an effort to get the cop off the hook."

Be at peace, Mokantx.  As explained above, the prosecutor could not have prejudiced the case by "aiming high."  In Missouri, as in many (if not all) jurisdictions, second degree is a "lesser included offense," so that if the only missing element were "deliberation," second degree murder would be the appropriate verdict, notwithstanding the original charge of first degree.