Can a patent be declared invalid on the grounds of prior inventorship by some other person?

As stated in s. 61(1)(b), no patent will be declared invalid on the grounds of prior inventorship by some other person unless the challenging party can establish that the other person had, before the issue of the patentee's patent, made an application for a patent in Canada on which conflict proceedings should have been directed. Stated in other words, a party may only successfully raise inventorship as an issue if: (a) the invention in the patent or claim had already "been known or used by some other person"; (b) the other person made a patent application for this prior invention in Canada; or (c) "conflict proceedings should have been directed". The interpretation of s. 61(1)(b) was the subject of discussion in the case of Laboratoires Servier v. Apotex Inc., 2008 FC 825, 67 C.P.R. (4th) 241 [Servier FC] .