Simple def, from FindLaw:
BBM
Second-degree murder is ordinarily defined as 1) an intentional killing that is not premeditated or planned, nor committed in a reasonable "heat of passion" or 2) a killing caused by dangerous conduct and the offender's obvious lack of concern for human life.
http://criminal.findlaw.com/crimes/a-z/murder_second_degree.html
There is the flaw in your argument, while Murray's conduct may have been dangerous (and hence the manslaughter charge) there is no evidence that it was motivated by "the offender's obvious lack of concern for human life".
Sorry, IMO there is no way this should be a murder charge.