Fout means “wrong” or “error.” Dutch records are pretty reliable in general but we should always look for multiple independently created original records to prevent one error from leading us astray.
In World War II, the word fout got a special meaning. It was used to indicate people who collaborated with the Germans. Many of them were prosecuted for collaboration after World War II. Their court records can be found in the Central Archives for Special Jurisdiction at the National Archives in The Hague. The records will become public in 2025. Until that time, you need proof of death or permission of the person involved to gain access (reading-room only).
For more information see Finding Collaborators in World War II.