USPTO Reliance Not Required for Argument-Based Estoppel?

According to "Patently Obvious: the MBHB Patent Blog," the Federal Circuit made the following statement in Lifestream Diagnostics v. Polymer Technologies, 03-1630 (Fed. Cir. 2004) (unpublished opinion):

"We hold that reliance by the Patent Office upon arguments made by the patentee during prosecution is not necessary to find argument-based estoppel.... Because we reverse some of the district court's claim construction, we vacate the court's judgment of noninfringement and remand."