Antony claims that Caesar died not just by the stab but by the betrayal too.
Step-by-step explanation:
For Antony, the great crime in the death of Caesar is that the people betrayed him.
For Antony he was the one person that thought of Rome so much and it was Rome itself that betrayed him and it is what has truly killed the man and not so much just the stab wound.
Anthony is trying to insist here the fact that the people must not forget the death of the man because they have done an error of judgement if they believe that he was to be a tyrant.