From your cited source "noting that U.S. tax professors Bernard Wolfman of the Harvard Law School and Martin Ginsburg of Georgetown University Law Center, concluded that no crime was committed, and that Rich's companies' tax-reporting position was reasonable.[9] In the same essay Clinton listed Libby as one of three "distinguished Republican lawyers" who supported a pardon for Marc Rich."
Besides Federal Prosecutor James Comey others were critical as well:
According to Paul Volcker's independent investigation of Iraqi Oil-for-Food kickback schemes, Marc Rich was a middleman for several suspect Iraqi oil deals involving over 4 million barrels (640,000 m3) of oil.[21] Longtime Clinton supporters and Democratic leaders such as former President Jimmy Carter, James Carville and Terry McAuliffe, were all critical of the Clinton pardon. Carter said the pardons were "disgraceful."