Credit to cadillacattack at ITAT for digging this up:
12.5.2.1 Advertisements and Promotions After Becoming a Student-Athlete.
After becoming a student-athlete, an individual shall not be eligible for participation in intercollegiate athletics if the individual:
(a) Accepts any remuneration for or permits the use of his or her name or picture to advertise, recommend or promote directly the sale or use of a commercial product or service of any kind; or
(b) Receives remuneration for endorsing a commercial product or service through the individual's use of such product or service.
12.4.4 Self-Employment. A student-athlete may establish his or her own business, provided the student-athlete's name, photograph, appearance or athletics reputation are not used to promote the business.(Adopted:12/12/06)
So, clearly Johns has forfeited his eligibility under these rules. The question, then, is what liability, if any, does Bama have?