It is best to talk to an immigration attorney before he leaves so he knows the consequences of this decision and perhaps to arrange a voluntary departure.
If he has never been before an immigration judge, nor arrested by ICE, it is not self-deportation.
Talk to a lawyer.
Most likely he can just buy a plane ticket and go home .... being aware of the fact that he can't come back for at-least 10 years ... without special permission.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.
No. Buy ticket and leave.
The information contained in this answer is provided for informational purposes only, and should not be construed as legal advice on any subject matter,not should it be viewed as establishing an attorney client relationship of any kind.