While we do not Support third-party hardware such as your Defender Recorder I can tell you that any device that has IR and accepts signals from an IR Remote is susceptible to this device that you mentioned as its simply a universal remote that tries different codes, you can basically do the same with a universal remote and set it to program mode and press the next code button which is usually the up arrow and this would either raise the volume or turn off the device you are programing it to , its not considered a hack its simply a small toy. Disconnecting the IR would do the trick, but cutting the IR may well void your warranty with its manufacturer or location that you purchased it with, it shouldn't interfere with normal operation, it will just impede you from using an IR remote.