A Governor must exercise power cautiously and be aware that calling for a trust vote could bring down the government, the Supreme Court said today in sharp remarks while hearing a case on the Shiv Sena coup. Hearing the Sena versus Sena case, the Supreme Court made strong observations on Governor Bhagat Singh Koshyari's role in the Maharashtra vote that unseated the Uddhav Thackeray-led government last year.