I have a theory that if your sig is on then the feature that turns off the allcaps will not work.
After i test this theory i’m going to make my sig allcaps and see if it still fails
also testing whether it works on the thread titlE
EDIT: HMMM… INTERESTING TEST RESULTS
My new theory is that the sig is only on by default in replies not in new post windows
Your title isn’t all caps.
Both theories out the window
so then this begs the question: Why did my allcaps reply in the other thread stay allcaps???
(pre submit edt: Hey cool - the error that tells you to wait x seconds now just appears on the same page you were on when you pressed submity.
Er… it appears to be on my browser.
The 'l’s are not uppercase. 
Look really closely at the word “AllCAPS.”
OK how on earth did that happen! If it’s an accidental press of the caps lock key and then accidentally turning it back on again then that’s one hell of a lucky coincidence to happen on a letter that’s difficult to distinguish from its capital cousin.