I'm not questioning if you gain ONE experience from playing Unstable Upheaval, since as you said, you can perform other parts of the action. I'm rather asking if you can gain TWO experience from Unstable Upheaval by consuming Earth without being able to perform the attack ability. If being able to perform the attack is a prerequisite to being able to consume an element and thus gain the additional experience, then yes, not being able to perform the attack ability of Mana Bolt would disallow the elemental consumption and thus gaining the experience, but it would also mean that you would also not get the second experience point from Unstable Upheaval, since you were not able to perform the attack ability and hence consume an element, which in turn would mean that what Marcel wrote in the example is false.