I'll paraphrase a few thoughts from Hassan's book Releasing the Bonds. No cult or high control group manages to get 100% control of it's members, if that were possible noone would ever be able to leave. It's important to remember this when determining if a given group is high control. Don't look for some complete emptying of personality, this is a false stereotype of cults. These don't really exist. Cults are recognized in part by unethical control thu fear of disapproval and abandonment. The subtlety of most cults is the 'illusion of control'. The individual thinks he is making his own choices when in fact he has been socially influenced to disconnect from his own critical mind and decision making capacity. This means everyone in a cult will tell you they have critical thinking skills and have made well thought out decisions. Being that the focus of the group is Salvation or acceptance, then small infractions of the rules that the individual has rationalized to be nonthreatening to this goal may be indulged in. This indulgence is not really independant thinking. It is rationalization. If the behavior is perceived as critical to Salvation or identity as a member the person under thought control will passionately shun the behavior. This is why, as was said, some DFd folks are still under the control of the group. They personally rationalized a behavior as non threatening to their identity as a JW or comartmentalized the behavior (double life). They were then shakened and shattered to find the Elders view things differently or see them ONLY as wicked persons with hidden sins.
Additionally the cult naturally produces a double self. The person they were pre cult and the image they sell to others and convince themselves is the new self. These mental gymnastics produce the sensation of unworthiness as we are semiconscious of our faking the cult persona. This means that every person under this cult influence does things that are forbidden by the cult yet this in no way is seen as a deliberate separation from cult authority by the person themselves. They see it as imperfection, something to be hidden, something to be ashamed of.
A matter like shunning of Apostates is loaded with explosive emotions. It has been linked by the WT to Judas Ischariot and Nazis. It is made inseparable from loyalty to the group and God. This is why even those DFd often shun those labled this way. It threatens the core identity as a JW and is nearly impossible to relegate to imperfection.