That's true of stream ciphers, and if they reuse a nonce.

It looks like they used 3DES which is for all intents and purposes here, immune to a this kind of attack.

EDIT: If they use 3DES in a CTR mode then it could be vulnerable to this, but looking at the base64ed texts in the blog posts, they are multiples of 8 meaning it is almost certainly in a block cipher mode. Would be interesting to see if you can find any block similarities if they used ECB.