Yes, if the children are returned to you, after proceedings, that is usually considered only a temporaray absence. But as others have said, it depends on the details.
In your case, the question is academic, because they were gone less than half the year. Even if it had been more than half the year, as long as no one else tries to claim them, you don't have a problem. The conflict comes when the foster parents also want to claim the child. If the child was legally placed with the foster parents for more than half the year, the IRS will usually side with the foster parents.
