My friend Bob was using the company's computer to download movies. He got caught 3 months ago, taken under disciplinary procedure and asked "Are you downloading files by using p2p software?" Bob denied it, although he knows he got caught because they mentioned the name of the software specifically.
Now, 3 months later, things between Bob and the management got ugly. And the HR called for another disciplinary procedure, and said "We recently(!) found out that you were using p2p programs at work. And we decided to fire you because of Gross Misconduct."
Are the companies allowed to hold the evidence for rainy days just like in this example? Are there any day limitations for them to use it after they find out?
Note: It's an EU country.