How can a patentee rebut the Festo presumption of surrender?

In Festo, the Federal Circuit (upon remand from the U.S. Supreme Court) explained that the presumption of surrender can be rebutted in three ways.  First, the patentee can show that "the rationale underlying the amendment [bore] no more than a tangential relation to the equivalent in question."  Second, the patentee can demonstrate that the alleged equivalent was unforeseeable at the time of the amendment.  Third, the patentee may rebut the presumption by showing "some other reason" why it could not have been expected to express the claim amendment in such a way as to still include what is now argued as equivalent.