Why should Damian McBride get any redundnacy pay?

So far as I can see, Damian McBride was a Civil Servant paid by the taxpayer not the Labour Party. He sent these allegedly libellous emails during working hours, from his PC at No 10 using Government equipment and the Government's secure email system.
Has he not therefore broken the Civil Service Code by using his office for inappropriate actions. As a Civil Servant, not a Labour Party employee, he should not have been indulging in party political matters.

If the above is true then Damian McBride should have been sacked for gross misconduct and so lost out on severance pay etc.

Furthermore could he not also be guilty of criminal offence: malfeasance in public office? Maybe a lawyer could advise on this and the possibility of taking out a private prosecution.