Hinjo's a smart cookie--I think Xykon's attack may help him realize how Soon's code has helped lead things to the invasion of Azure City, rather than protect it. Soon seemed too Miko-ish in mindset to admit that his way could be wrong--he also was motivated more by revenge than anything else (with his beloved's death). I think Hinjo may not care for the OotS after this, but I don't think he'll equate them with the pure nastiness of Xykon and his forces like Miko did. And, anyone who could make a high enough Knowledge (religion) check could probably tell him that liches have phylacteries, which is why the OotS thought they destroyed Xykon but hadn't