Those that have been paying attention know that comex is known to be one of the only non-twiizers to have an IOS exploit. I remember the day in #wiidev when he mentioned he found it, and marcan himself on hackmii has mentioned that if people want an IOS exploit, they should find it like comex. So I don't doubt that comex has an exploit, the removal probably had something to do with twiizers asking him to take it down because bootmii probably won't be ready before the next sysmenu update (you guys still working on that EXI thing?)
this is all just me guessing though, but comex was a member in my #bliight channel for a while and I remember when he was disassembling the IOS by himself, so this isn't too far fetched.