The same way John Adams lived with himself when he defended the British soldiers responsible for the Boston massacre. I'm not defending nor applauding the defense attorneys, but I'll say this: We could have something more akin to Sharia if we did away with them.
There's one big difference between John Adams and these defense lawyers: Adams' clients hadn't plotted to commit murder. According to David McCullough's biography of Adams, the British soldiers weren't responsible for the riot. A group of 8 soldiers was cornered by a group of colonists, who began pelting them with oyster shells, stones, snowballs, etc. The colonists closed in on the soldiers, two of whom fired at them in self-defense, killing them.
I understand the point you're making about everyone deserving a fair trial. But the defense attorneys in this case shouldn't be celebrating their victory in keeping their client from the death penalty. They should be soberly reflecting on the fact that doing their job has in this case resulted in sparing the life of an evil man who would be happy to see every American, including his own defense attorneys, be murdered.
In my opinion, the law has been upheld, but the higher good has not been served.