Veteran Hollywood film stars paid tribute following his death including Clint Eastwood, who directed Hackman in western film Unforgiven, and Francis Ford Coppola, who wrote and directed the Oscar-nominated 1974 mystery thriller The Conversation, starring Hackman.

The decision about which stars are included -- or excluded -- from the tribute at the Oscars comes down to time.

Set to a live performance of Mozart's "Requiem – Lacrimosa," the In Memoriam segment presented by Morgan Freeman ... absent from the segment was Michelle Trachtenberg, who died on Feb. 26 ...

Michelle Trachtenberg was notably left out ... Those honored in the Morgan Freeman-led segment included Maggie Smith, Gena Rowlands, Teri Garr, Donald Sutherland, Louis Gossett Jr., Shelley ...

Celebrities excluded from the Oscars In Memoriam tribute is causing a stir online. On Sunday, Morgan Freeman presented the segment at the Academy Awards, which honored actors and filmmakers who died over the last year including Gene Hackman, James Earl Jones, David Lynch and Maggie Smith.