Alas, Loki's runaway is still broken with patch d. It comes up that he retreats, but also that he is destroyed. After the combat, he is gone, so destroyed wins out over running away.
edit - after reloading the same game, he was later attacked by an assassin. He did run away, but was damaged in the attack. In previous versions, I don't remember him ever taking any hits.
edit - after reloading the same game, he was later attacked by an assassin. He did run away, but was damaged in the attack. In previous versions, I don't remember him ever taking any hits.