I wonder how they are going to monitor whether he puts Ubuntu back on anyway, if you think about it, it doesnt take a minute to remove a hot swap hard drive, in fact it doesnt even take a minute to swap over a hard drive in a half decent PC case (Antec, Lian Li etc). Even quicker in a lot of laptops lol.
All he has to do is install Ubuntu on another HDD, and then use that one. Get a cheap ass security cam over his door, and when someone knocks, see who it is, and if its the enforcement officer, swap the hard drive to the Windows one and hide the Ubuntu HDD hehe.
I hope he wins to be honest, because if they can't monitor the OS he uses, they shouldnt then remove his right to freedom of choosing what OS he wants to run, they should instead develop the monitoring software to work with the OS he chooses to use.
Tis deffo gonna be interesting to see what happens.