I already sent a Bug Report In-Game but not all Priest will see this, the new Expert Skill (Redemtion) causes a Graphical Glitch on the HP Bars of everyone that is healed over his Maximum HP (or something like this). The affected will see that his HP will not decrease even if hitted but this bug can stack indefinitily until you die with, for example, 60% HP of your total. (I think it Heals OVER your Maximum HP but only Graphically speaking)
This Skill actually heals but this graphical glitch can cause you to die because you can't see your current HP.