Lets imagine there is a person called George that works for the dutch government to secure their ICT systems. The government body he worked for was not a secret agency or something like that. This George does this work for over 8 years. About 5 years ago, he made some sort of more or less innocent computer virus, that he might also spread.
This was all done during a holiday in another country. Now by some reason (unrelated to this computer virus or some similar event) he is fired by his boss. George became emotional, goes to a bar and drank too much alcohol. He became drunk and told someone in the bar that he got fired, while he actually has made (and possibly spread) a computer virus, which is (in this scenario, but probably also in reality) against his work-contract. However no one ever came to knew that. He became so mad, or emotional that he started to write that fact(the virus) as a small blogpost on his blog.
Now lets imagine that due to circumstances that next morning he more or less forgot about his blogpost(at least until the court meeting). His former employer, however came to know this post because he either likes reading that blog, or there was talked about in his government body.
George went to court because he finds his situation unfair(which it might or not might be). To him, he just wants to continue his job, so that is what his charge is about.
Now let's assume that his former employer knows about the post before he goes to the court-house. They all have to appear in court together. Would it make sense for George's boss to just talk about this blogpost, or not for he was fired for another reason? If this is the case, what are the most reasonable reasons not to disclose (the fact that he made a virus) to the judges?
This virus that George has made/spread had have was not targeted against nor had real big impact on his or other dutch government computer systems.