Server sided detection?

Alright so this is what happened. Some guy posted(I don't remember who) that you can still log on to the game if you keep your old client running through the patch. I still had the old copy of Vindictus on my desktop after the patch but that was just it. it wasn't running. so i dced my internet and ran the launcher and it said it couldnt read some text file hosted on the nexon site. after looking for a little bit and tinkering with the NGM text file i could redirect that check too the old text file that i hosted on my webserver. so i googled the original address of the UpToDateInfo and i was lucky that google hadnt updated the little description of the site so it still had the original text before the patch, which was this
so i made a text file popped it in into my webserver, dced the internet and ran vindictus. It worked assuming that their was no update. closed it again, reconnected my internet connection, opened up my injector, injected Nico's dll and Dcommands. it worked, got into the game started up a boat and tried that commands. before i even did anything it said something along the lines of unauthorized program detected. i quickly did some hacks and they worked but i was shortly kicked from the game.

So is this server sided detection? I'm thinking this because these are purely client modifications.