There is a difference between integrating the CCM with AD to use as the directory and having the CCM servers in the Domain. For more on this please refer to the following chapter from the 4.0 SRND:
http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_implementation_design_guide_chapter09186a00802c37ae.html
To answer your question.....
Yu can uninstall the AD plugin and revert to using the built-in DC Directory. You may have to add users, etc to the DC Directory, just depends on what was configured previously. Once the AD is stable you can reinstall the AD Plugin and the user information that is in AD right now will stil be there, assuming that nothing is lost while fixing the AD.
Kevin