Is it possible that some push effects also have a bind component to immoblize us. Rescue can't be used on bound players and most forced movement keeps you from being able to walk around. Like the tilt on Leviathan or Sophia for instance. It doesn't say you are bound or stunned but you definitely lose control of your character. I wonder if there is a hidden mechanic to some forced movement that keeps Rescue from being used until the mechanic is over entirely.