The defendant was drinking in a bar after a breakup with his girlfriend. Another patron was also drinking and became intoxicated. The patron then approached the defendant and demanded that the defendant buy him another drink. The defendant refused. The patron then grabbed the defendant's arm and began yelling that the defendant was a cheapskate. The defendant forcibly pushed the patron's hand away, causing the patron to fall to the floor. In his drunken condition, the patron hit his head on a barstool and died. What crime may the defendant be convicted of