Sunder Armor / Expose Armor interaction

[Maikie1234]

Describe the bug
If a rogue tries to apply his Expose Armor on a target that is aleready affected by Sunder Armor and said Expose is weaker than the Sunder stacks, the cast of Expose will still go off --> rogue uses his energy and loses his combo points

Character name
Aretha

To Reproduce

1. Warrior casts Sunder Armor (max rank - Rank 6) on a mob
2. Rogue uses weaker Expose Armor on the same mob --> the Expose reduces less armor than the Sunder stacks
3. Rogue loses combo points and energy, the spell goes off, but expose doesnt get applied on the mob because there is a stronger armor reduction

Expected behavior
There should be an error message saying "A more powerfull spell is aleready active" or Expose shouldnt be castable at all

Not sure if it expected behavior on this client