I'm building an Rogue duelist and have a question about the lvl 9 daily: Profit from Weakness
Profit from Weakness
You step aside as the enemy’s attack sweeps toward you. You then slide your blade into a place where the foe is vulnerable.
Daily * Martial, Rattling, Weapon
Immediate Interrupt * Melee 1
Requirement: You must be wielding a light blade.
Trigger: An enemy adjacent to you hits you with a melee attack
Effect: You gain a +4 bonus to all defenses against the attack. The triggering enemy grants combat advantage to you until the end of your next turn.
Target: The triggering enemy
Attack: Dexterity vs. Reflex
Hit: 2[W] + Dexterity modifier damage.
Miss: Half damage.
Effect: You knock the target prone.
So I have a +4 bonus to all defenses but now I wonder, does the enemy also gets a -2 to attack for attacking while prone? Because I interrupted his attack and knocked him prone before his attack hits me, but that doesn't seem right.
So I would like an explanation: does he get the -2 penalty or not, and why?