If the translation of TaiG's letter is accurate, it sounds like their program has code containing the necessities for the 8.2 jailbreak. Remember, Apple is a huge company, which means they have a very large security team which is paid to find and fix iOS vulnerabilities. That being said, maybe TaiG obfuscated the code, or the translation is incorrect and instead is saying that they have found exploits but held them out of the current jailbreak.