Different people perceived the events of the Boston Massacre differently because of their political ties. The loyalists who wanted Great Britain to rule over them saw the event as an accident. The patriots who wanted freedom from Great Britain saw this event as an intentional act for the Red Coats.
The reason for the differences in what happens at the Boston Massacre is because through out the chaos no one knows exactly which side fired the first shot. This led to many accounts of which side fired first. Also, some people many have let their political views sway them as to what happened that night.