With reference to the law of evidence, which one of the following is not a case on Estoppel?

Palvinder Kaur concerns the treatment of a purported confession and the proof needed for criminal liability, not the doctrine of estoppel. Pickard v Sears is the classic representation/reliance authority; the university permission dispute in Shri Krishan and Sarat Chunder Dey’s representation principle belong to the estoppel line.

The general estoppel rule is now in section 121 of the Bharatiya Sakshya Adhiniyam, 2023 (formerly section 115 of the Indian Evidence Act, 1872).