Sec. 29. (a) The department and its authorized inspectors and agents may investigate the age of a minor who is employed or allowed to work in an occupation.
(b) If the department or its authorized inspectors and agents find that the age of the minor is below the age authorized under this chapter, the:
(1) employment; or
(2) fact that the minor is allowed to work;
is prima facie evidence of unlawful employment.