I was the first to post an algorithm after which the 'bruteforcing' can be applied (see posting 2093 https://bitcointalk.org/index.php?topic=661781.msg7704707#msg7704707)

(Many others were stuck at the same step privately.)

The next step was to iterate over every position in input string (z69JZqlJn862D1ndx7oLVEMmVOlP1zewEeUCrsI7Roahzpeny7P) and, if the character was a lowercase character, change lower case to upper case and run the algorithm again. Then if the corresponding public key matched, you found the answer. (This happens when you turn the 'w' into 'W')

I would not classify this as 'bruteforce', actually, since the problem space is so tiny. Even if you iterated over every position and rotated through all 128 printable ascii chars, it can still be done in a matter of milliseconds (provided you had a quick way to generate the public address from the private key, which I did).

My initial reaction was that it was a mistake.  But now that I thought about it, I think it was intentional.  It was just one more barrier.

My beef was that there was no _reason_ to attempt this type of mutation until the OP gave the final clue 'what was once tall is now small'. But in retrospect, it was not that much of a leap to try that. I tried so many other dumb approaches.