The only way for patent owner to respond to testimony presented in a petitioner’s reply is through a Motion for Observations.  A motion for observation on cross-examination is a mechanism to draw the Board’s attention to relevant cross-examination testimony of a reply witness. The observation must be a concise statement of the relevance of precisely identified testimony to a precisely identified argument or portion of an exhibit (including another part of the same testimony).  In Medtronic, Inc. v. NuVasive, Inc., IPR2013-00507, Paper 33,  IPR2013-00508, Paper 37, (October 15, 2014), the Board found that the motions for observations filed by patent owner “contain arguments and are excessively long, and, thus, improper.”  The Board expunged the Motions, but graciously allowed patent owner a chance to file corrected Motions.