Can a judge rectify a will to fix a lawyer's drafting mistake instead of striking the whole clause down?

Yes. Ontario courts recognize a remedy called rectification, which lets a judge correct a will's wording where a genuine clerical or drafting error means the document doesn't actually reflect what the testator intended — for example, a lawyer's transcription mistake, an accidentally omitted clause, or wording that produces a result the testator clearly never asked for. Rectification is narrow: it fixes the document to match the testator's actual, provable instructions, rather than rewriting the will to reflect what a court thinks the testator probably would have wanted in hindsight.

This is a separate tool from the court's newer statutory power to validate a will that was never properly signed or witnessed in the first place — rectification instead addresses wills that were correctly signed and witnessed but say something the testator didn't intend because of a mistake in preparing the document. To succeed, the person seeking rectification generally needs solid evidence of the testator's actual instructions, such as the lawyer's drafting notes or earlier correspondence, since courts are cautious about rewriting a signed legal document after death. Anyone who suspects a will contains a drafting error, rather than reflecting the testator's real wishes, should get legal advice promptly, since gathering the file and evidence early matters.