Speaking of sympathy functioning as a trump card, here's an excerpt from the 1885 English court decision, Regina (The Queen) v. Dudley and Stephens. Better known as the Case of the Mignonette, Dudley and Stephens were put on trial and found guilty of murder after engaging in cannabalism. Shipwrecked and adrift in a dinghy on the high seas, Dudley and Stephens agreed to stab and eat the fourth survivor, a cabin boy named Richard Parker. Although he shared in the spoils, a third survivor, Edmund Brooks, didn't consent to the killing and thus was not tried for the crime.
It must not be supposed that in refusing to admit temptation to be an excuse for crime it is forgotten how terrible the temptation was; how awful the suffering; how hard in such trials to keep the judgment straight and the conduct pure. We are often compelled to set up standards we cannot reach ourselves, and to lay down rules which we could not ourselves satisfy. But a man has no right to declare temptation to be an excuse, though he might himself have yielded to it, nor allow compassion for the criminal to change or weaken in any manner the legal definition of the crime.
Truth and compassion existed in a largely harmonious relationship in the past, but in our time compassion has become malignant.