Doubt
One of the most pernicious effects of domestic abuse is that it robs the survivor of the sense of reasonable certainty. Primary aggressors usually discover that they do not need to convince others of their point of view, but rather it is only necessary to sow doubt. Most people have trouble taking strong action against a pressured stance if they have any doubt. Even professionals working with primary aggressors fall into this trap.
It is not necessary to be free of all reasonable doubt in order to set boundaries or take steps in one's self-interest. One's life is not a criminal justice proceeding. With some experience, primary aggression is immediately recognizable on a subjective basis. It is noticeably more difficult to describe and 'prove' primary aggression on an objective basis, though this website is designed to assist in that.
Once any effort to confront primary aggression starts, efforts to instill doubt will escalate. It is possible for the entire helping community and the extended family to mysteriously take this on and start to doubt one another.
Offender treatment of all types was originally designed to begin with a sincere admission of responsibility. Treatment could not continue until that was forthcoming. However, with pressure for all primary aggressors in legal trouble to enter treatment, that requirement was dropped. Now, treatment is considered successful if it ends with an admission of responsibility instead of beginning with it. Perhaps this results in a greater number of admissions of responsibility and is ultimately beneficial. However, it means that the entire community battles with doubt throughout the whole undertaking.