1, because of the quarrel, one person died, there will be a forensic appraisal, if the forensic appraisal book, the deceased did not have the trauma caused by your friend pushing him, the appraisal conclusion is that the deceased died of a heart attack, then your friend is not criminally responsible. 2. According to your statement, your friend didn't push the deceased, and the other party owed your friend money. Your friend's debt collection was a legitimate reason, and your friend's husband knew that the deceased had a heart attack, so it was also a legitimate act to drive someone to the hospital.
3. The only fault is that when collecting debts, you open the car door from the co-pilot side and want to pull out the car keys of the other car. In this case, if the other party's asking price is too high, if negotiation fails, wait for the judgment of the people's court, that is, your friend will bear as much as the court decides.