The vulnerability
was open sourced before he did it thus apparently no insider information was used! Even the developers of DAO had a patch but didn't push through with it.
It is so unbelieveable, but I can't make this stuff up.
While the patch fixed the vulnerability in one part of the code, amazingly it overlooked the same vulnerability in another part, and it was there that it could be (and was) exploited to drain funds.
One ponders have they no
find in files in their IDE?