Sua morte tem sido um mistério até a data na vida real. O mesmo mistério é mantido no filme.
Ao invés de tomar a liberdade de retratá-lo de acordo com o desejo do escritor / diretor, eles optaram por não fazê-lo. E eu estou feliz que eles fizeram isso.
Citações de Estudo avançado em a história da Índia moderna, 1707-1813 (página 125):
After the conclusion of the war, the Peshwa sent Chimanji Appa back to Poona while Balaji Baji Rao was deputed by him to proceed to Kolaba to settle the property dispute between the Angre brothers. The Peshwa himself retired to Raver, on the southern bank of the Narmada, where he was struck with 'virulent fever', and breathed his last on 18 April 1740. On the receipt of this sad news, Mastani died within a couple of days, 'whether by suicide or of shock, it is difficult to say'.
(Footnote: According to some, Mastani committed sati on her husband's funeral pyre.)
(ênfase minha)