Consider the following method from a business layer.

public async Task<OneOf<NotFound, NotDeleted, Person>> DeletePersonAsync(int id, CancellationToken ct)
{
    var person = await _db.People.FirstOrDefaultAsync(m => m.Id == id, ct);

    if (person is null)
        return new NotFound(id,"Person"); // ===> 404 NotFound

    _db.People.Remove(person);

    return await _db.SaveChangesAsync(ct) > 0
        ? person // ===> 200 OK
        : new NotDeleted(id, "Person"); // ===> 409 Conflict ???
}

I am not sure whether SaveChangesAsync() can return a non-positive integer in this case. Maybe because of race condition?

If it does really happen, what is the proper status code for it? 409?