If he has custody of the children after this, which is likely due to the fact that he made her doubt her own memories and actions, making her feel like a fool in court, he will continue to use the children in his effort to control and manipulate her. When she goes to pick the children up, he will use it as an opportunity to create unnecessary drama. Perhaps she didn't give him the right name for her apartment complex. Perhaps she has requested that she be given some measure of privacy, so he tells the children that this is a sinister act, so suddenly they need a cell phone to "escape" their evil mother. He tells lies to the children then accuses her of being the liar and teaching the children to lie. Covering up a surprise that she wishes to give the children suddenly becomes an act of pure evil.
The mother is left thinking, "I know I didn't lie to the children, why is he accusing me?" She finds herself questioning her own motives. A person like this can turn a fun trip into an act of pure evil. He will convince the children that they are being manipulated by her, when he's the one doing the manipulation.
All of this sounds pretty scary, and it actually does happen to both mothers and fathers, although more frequently to mothers than we'd like to admit. The good news is that there is light at the end of the tunnel. Although the relationship with the children may never be the same as it was, the longer you are away from a gaslighter, the stronger you become. You stop questioning your own memory as his hold on you is loosened. You learn to think clearly again without his constant influence. You learn to tell the truth in spite of the fact that he's accusing you of lying and false allegations for doing so. You keep hope alive that
someday your children will understand all that you are going through and have gone through, and love them unconditionally, even if you don't like everything they do under their father's influence. You may also use it as a learning experience to pass on to others so that others don't have to suffer as you have.