Hmm... this is actually just a copy of the functionality found in phpBB 2.0.11, which I hadn't realized would be case sensitive. I didn't test that out myself, strangely enough, I suppose I'd just assumed.
Since the MOD doesn't use both uppercase and lowercase letters, you're right. I'll look into it, perhaps they changed that for 2.0.12.
Ultimately, what would be ideal is to move the functionality into functions somewhere that makes sense, rather than the stuff sitting in the calling pages and profile.php. As it is, this MOD is completely guilty of code duplication, and sort of turns visual confirmation into spaghetti code. But this is the method that requires the least work to implement, even if it is a little ugly on the backend.
I sort of wish visual confirmation hadn't been implemented permanently in 2.0.11, just so something a little more fleshed-out could have been figured out. Then again, nobody saw this coming