Likely to be both.
However in your "article" about it you say that he only accused the leaked Mr. Wiggles mod of having a backdoor. Since anyone running it on their server is a moron, I don't feel bad about telling you all that the backdoor is "/cakemix" and it's an eval backdoor, so go right ahead and /cakemix crash(); as many stuffty love RP servers as you like.
However in his defense, Tezuni wasn't the one distributing it; it was someone whose name started with M (lol). Mystery Guy or something, or so Drak said. This is of course off the top of my head entirely, don't freak out if it's the wrong person or anything because that's pretty likely, but I'm sure it wasn't Tezuni himself. Whether or not Tezuni put the backdoor in himself remains to be seen, or hopefully along with him, not seen.
As to this whole thing, Flaw did claim to have found "how Blockland confirms keys are valid" by opening Blockland.exe with Notepad. I'm personally pretty sure that whatever information there is to be gleaned from what you can see there is useless. Here's the conversation where he bragged about this petty achievement to me (pulled from my Pidgin logs):
1/6/2011 2:50:27 AM
(2:50:27 AM) [c=#FF0000]F|•w[/c=#FF6666]: Hey.
(2:50:35 AM) [c=#FF0000]F|•w[/c=#FF6666]: I found the pattern on how BL thinks that keys are valid.
(2:50:42 AM) [c=#FF0000]F|•w[/c=#FF6666]: stuff from exe snipped in case
(2:50:46 AM) [c=#FF0000]F|•w[/c=#FF6666]: damn you, msn max length
(2:50:55 AM) [c=#FF0000]F|•w[/c=#FF6666]: stuff from exe snipped in case
(2:52:33 AM) Cenric: I assume you mean the first five digits, in which case you're about a year late to the party.
(3:33:22 AM) [c=#FF0000]F|•w[/c=#FF6666]: Not only the first five.
(3:33:39 AM) [c=#FF0000]F|•w[/c=#FF6666]: Look in Blockland.exe, from line #### off
(3:39:58 AM) Cenric: And you perceive this information as useful how?
(3:40:01 AM) [c=#FF0000]F|•w[/c=#FF6666] has become idle.
Cenric obviously being my screenname at the time. He has a tendency to make stuffty and/or useless client scripts then brag about them to people; something I think he inherited from MegaScience. He also does not seem to grasp the concept of other people not needing to see the input or output of client scripts only he can use, as many times as I had explained this to him.