Gah! Completely forgot about Prohibition! And we all know how that turned out.

It may be not dismantling an industry, but the state nationalizing an entire sector of the industry or service at once have not been unfrequent in France during the last 150 years (this may be kind to what your friend has in mind):

• The private railway companies and most of the military-industrial complex in 1936-1937 (3rd republic, a coalition of the left parties in power)
• The whole energy industry between 1944 and 1946 (under a union government, going from the right to communists): mines, electricity and gas industres
• 5 biggest banks in 1945; insurance companies in 1946 (same government)
• Most banks in 1982 (union of left parties)

Each among these was done under democratic governments. There are other examples, but I can't find sources for these right now

Sources :

• military industrial complex, 1936 : Journal officiel de la république française, August 12, 1936
  http://gallica.bnf.fr/ark:/12148/bpt6k6550160d/f2.image and http://gallica.bnf.fr/ark:/12148/bpt6k6550160d/f3.image
• railway companies, 1937: Journal officiel de la république française, September 1, 1937
  2nd column, 4th item : http://gallica.bnf.fr/ark:/12148/bpt6k6550215x/f5.image
• mines nationalistion, 1944, GPRF Ordnances and Decrees; found on the french culture ministry site
  http://www.archivesnationales.culture.gouv.fr/camt/fr/memoires/donnees_expositions/06_11_06-07_07_27_mines/expo_virtuelle/html/exploitation_charbon/nationalisation.php
• electricity and gas companies, April 8th, 1946 : Legifrance
  http://www.legifrance.gouv.fr/affichTexte.do?cidTexte=JORFTEXT000000868448&categorieLien=cid
• insurance companies, April 25th, 1946: Legifrance
  http://www.legifrance.gouv.fr/affichTexte.do?cidTexte=JORFTEXT000000693626&dateTexte=19460430
  -banks (1), December 2nd, 1945, Legifrance
  http://www.legifrance.gouv.fr/affichTexte.do;jsessionid=9366EABD2129795B4FE380849481E86D.tpdjo03v_1?cidTexte=LEGITEXT000006072686&dateTexte=20101130
• banks (2): February 11th, 1982, Légifrance
  http://legifrance.gouv.fr/affichTexte.do;jsessionid=02FBD82C3CBCBFBE18A84B50DD08A420.tpdjo15v_2?cidTexte=JORFTEXT000000503960&dateTexte=20140528&categorieLien=id#JORFTEXT000000503960

Disclaimer : I'm not an historian, and my sources here are just legal texts found thanks to wikipedia datas and some archeological excavation through french legal archives found on the net.

Would the end of slavery in the United States count for this?

A good example that would be similar to an end to the current Health Care system was the American Savings + Loans crisis. Like Healthcare, S+Ls operated in an environment full of government regulations. Changing those regulations will have big effects on the industry. The US government wrote the regs which built the S+L industry up, and when it crashed, it wrote laws that changed it drastically. It also took over many failing S+Ls and sold off their assets.

A great deal of Healthcare dollars come from Federal programs like Medicaid, Medicare, Veterans Programs, etc. They also have quite a number of regulations governing care, etc.

S+Ls grew quickly in the early 1980s due to a number of financial regulations being loosened. Rules were made to specifically benefit this one type of bank.

Later, when the S+L Crisis hit in the late 80s(which happened for a slew of reasons, not needed to be discussed here), the government drew up another set of regulations which made the business far less favorable. This was on top of many, many S+Ls going under. They went from about 3200 S+Ls to 1600.