Halliburton...responded...to court filings by BP saying: BP recently filed a motion for sanctions against Halliburton alleging that Halliburton destroyed evidence relating to post-incident testing of the foam cement slurry. BP has been aware of post-incident tests for some time, but has chosen this late date in the litigation to mischaracterize the results of such tests. Contrary to BP’s assertions, the post-incident testing referred to in its motion was not conducted on rig samples or in a manner approved by Halliburton. Rather, the informal testing BP refers to used off-the-shelf materials that yielded results which Halliburton believes have little or no relevance to the case, particularly when pre-incident testing using rig samples and formal lab processes showed that the cement slurry was designed to be stable. In September 2011, the U.S. Department of Interior reported testing done on the actual Deepwater Horizon rig sample, confirming Halliburton's position that the slurry was designed to be stable. The Department further concluded that the cement likely did not fail in the annulus part of the well.