Based on the provided legal document, here are the key points with their corresponding references:

• The Supreme Court held that an adverse presumption regarding the genuineness of a cancellation deed cannot be drawn merely because the testator chose to append their thumb impression instead of a signature, as forgery of thumb impressions is nearly impossible and every person has a unique impression (!) (!) (!) .
• Objections regarding the admissibility of a registered document or the mode of proof must be raised at the earliest stage before the trial court; such objections cannot be taken for the first time in an appeal (!) (!) (!) .
• If a party fails to object to the production and marking of a certified copy of a document in the trial court, they cannot later claim non-production of the original in appellate proceedings, as this would prejudice the party who produced the copy (!) (!) (!) .
• The High Court erred in disbelieving the registered cancellation deed by drawing an erroneous presumption of impersonation based on the testator's alleged poor health, without giving due weightage to the evidence of attesting witnesses and the expert report (!) (!) (!) .
• The Trial Court was correct in concluding that the testator was medically fit to execute the cancellation deed, as the testator's thumb impression was proved genuine by an expert and there was no evidence of impersonation (!) (!) (!) .
• The appeal filed by the objectors (legal heirs of the probate applicant) is allowed, the impugned order of the High Court is set aside, and the judgment of the First Additional District Judge is restored (!) (!) .