ContentID takedowns are not DMCA takedowns. They operate on a different, much less strict standard. Anyone that works with YouTube can flag any video for any reason (see Scripps taking down a public-domain NASA video[0]), and the content is removed immediately without giving the initial uploader a right to contest it (it can be restored laterº. A YouTube user has way fewer rights under ContentID than they do under the DMCA. If you are found in violation of ContentID, you must fight both YouTube and the claimant to have your case heard under the DMCA.
[0] http://motherboard.vice.com/blog/nasa-s-mars-rover-crashed-i...