There are sometimes other reasonably valid reasons to do stated income other than self-employment.
True story … (The names have been changed to protect the innocent)
Joe Blo transferred with his company to a different city and Mrs. Blo switched jobs in the process. She essentially had one lined up, but obviously could not show income with check stubs because she hadn’t started yet. Her income from the old job would not pass muster for underwriters for a full-doc loan because they were buying a home several hundred miles from her current job. The Blo family did a stated income loan that actually reflected their actual income on what is commonly referred to as a liar’s loan. Sometimes I think they are the only suckers who did this.