Penelope
what doesn't kill me only makes me MORE CHIC
The wife took suicide pills and gave some to the dog because she was SICK OF HIS SHIT, and Gene Hackman died of grief from the loss of the dog 

It seems relatively plausible. Wife dies in accident or takes her own life. Gene goes for help, falls, and dies.My current theory is that the wife died in a freak accident - either collapsed or the heater fell on her head (although apparently no obvious signs of injury). Dog ate the pills nearby and died. Gene Hackman found his wife dead and ran for help but fell, then died from the fall a few days later.
Gene got the beginning AND endThe question now remains, who is getting the coveted final spot at the Oscars In Memoriam segment on Sunday? Maggie Smith, James Earl Jones, or now a late contender with Hackman?
A MOUSE caused THREE deaths?!