Sadly that was confirmed to be Mickey way back in KH1. Mickey called out to Riku but got Sora. That's why you have that added scene in KH1Fm of Riku wandering the dark realm after Ansem boots him out of his body where Riku also hears the voice and the voice goes on to explain it has the other key (KKD) and ha been trying to reach him for some time.
Roxas can be explained as Roxas remembering Sora's dive.e
There may be something wrong with me too. I'm a rather vindictive individual. It's hard to make me that angry but when one does I'm all for following the philosophy of treating others how they treat me or others.
Just hearing things like those fathers did makes me wish they'd get the same in turn or many more worse things I thought of in the 5 seconds it took me to read those messages. >: