If this is a third DUI, he really needs to hire an attorney. All the "stipulation" means is that he was offered a plea agreement to 180 days of jail with an authorization for work release. Keep in mind, that in Denver, work release is not guaranteed and must be applied for through the sheriff's office.
Moreover, taking a plea, automatically revokes his probation.
Lastly, the case may be a case that should be tried to a jury. Only by having an attorney look into the case, will you have any idea of what real options you have available.
Nothing in this communication should be considered legal advice. Nor should this communication lead you to believe that an attorney-client relationship has been created. Only after thorough analysis of your case with you in my office can I provide effective legal advice on your specific issue.