Third, and most important, is your definition of "matching"/"range" between IPs used by me and those used in attacks is simply ridiculous. If I used 100 web proxies, and then one of the IPs from attack is somewhat close to one of web proxy's IPs, then what is the meaning of that? None.
Lol, not really. And yeah, you need to see the ip range (I highly doubt Poss would have claimed for consistency against 1/100 ip range combinations), but what are the chances of you using that range of ip dresses both in-game and on the forum (as stated by Poss) and then have another device using that range for the ddos in practice, in a matter of time of maybe a day or two? They're rather low...besides, you said your ip originated from web proxies use (which in fact i doubt), I don't think whoever did that ddos would have needed to use such a thing, or use services from a company that also offers web proxies. Using a web proxy for that kind of thing would be a funny thing to do

unless she/he was too stupid.
Lol, and again you talk about a VPN ip as if the fact that one user playing the game and someone attacking the auth using the same ip range were totally a "random" thing. Its not, surely not with that timing....