In a stinging 13-page dissent, a Manhattan appeals judge has criticized a decision to cut almost in half the 16-to-32-year prison sentence a defendant received for masterminding an elaborate, multi-million-dollar diamond scam.

Justice Peter Tom of New York’s Appellate Division, 1st Department, wrote that the majority’s leniency was misplaced, considering the potential damage the defendant wreaked on the culture of trust in the diamond industry, where million-dollar deals are secured by only a handshake.