While I know that I don't see eye to eye with some regards the freedom of speech issue here, the punishment seems hugely dispproportionate to the offence. Is there anywhere which discusses the reasoning for the length of punishment awarded? I agree with Athena - this is essentially a backhanded way of expelling him.
I disagree with the kind of protest in which they engaged - basically 'who shouts loudest wins the right to free speech' - but such strong punishment suggests to me that Cambridge is trying to frighten all its students into being submissive and not to engage in any kind of protest. As a public body, can they be subject to judicial review for this kind of decision? I can't remember what the admissibility criteria would be for such a kind of hearing.