Can parties demand examinations for discovery in an Ontario will validity dispute?

Yes. Once a will challenge becomes a genuine contested court proceeding, rather than a routine, uncontested probate application, the general civil litigation tools that apply to most Ontario lawsuits become available, including examinations for discovery — the process where each party can question another party, under oath, about the facts relevant to the case before trial. In a will dispute, this often means the estate trustee, the person challenging the will, and sometimes other beneficiaries can be examined about what they know regarding the testator's capacity, the circumstances in which the will was made, or their own involvement.

Examinations for discovery are a significant part of why contested will validity cases can become lengthy and expensive compared to an uncontested probate application: they typically follow an earlier stage of exchanging relevant documents, and the transcripts from the examinations can later be used at trial. Because what's said (and what documents are produced) during this stage can shape the rest of the case significantly, careful preparation matters, and answers given under oath can be difficult to walk back later. Anyone facing an examination for discovery in a will dispute should prepare with their lawyer in advance rather than treating it as a formality.