I was always taught you're supposed to do that -- high notes are more penetrating than low notes, so you either back off the volume or pull the mike away. Nothing "dramatic" about it, it's just to keep the high notes from being overpowering.
Yes, but -- go back and look at the recording if you still have it. You'll see other singers back off the mike a little, say five or six inches, so they don't blast the mike. The way he's backing it off, he'd have to be Pavarotti! (I watched an Idol-like show for young opera singers lately, and their mikes [hanging mikes] were about two feet away!) Also, he's not backing off the mike as the note builds -- he's giving just an instant of the note and then holding it about a foot away, so you don't hear the whole note. Just not cricket, IMHO. (Though effective, apparently, since only loons like myself are paying attention to it! LOL!)