Can a person who is compelled to kill by another person receive a lesser penalty

here is the situation: After cross-examining the Crown's witnesses, the defense would call Jeff Taggart to testify with the motivation of revealing a severe methamphetamine drug addiction. While on the stand Taggart would continue to reveal that his drug addiction has numerous symptoms including frequent and vivid hallucinations and periods of delusion. He also would carry on to testify that powerful drug lords were funding his drug addiction. The same drug lords who hired him to kill Adam Bouncer, to repay financial debt. If the job was not completed Taggart was informed he would receive bodily harm or would be killed.