The transcript of the interview is here:
http://news.bbc.co.uk/1/shared/bsp/h...1011201302.pdf
In terms of the suggestion that he's calling for the maximum sentence:
MARR: So you’re not ruling out personally the idea of clemency by judicial process, in the proper process?
GENERAL SIR NICHOLAS HOUGHTON:
No, what I’m saying is that those who are in authority over the armed forces ...
ANDREW MARR:
(over) You can’t call for it?
GENERAL SIR NICHOLAS HOUGHTON:
... should not request any form of leniency. In fact I think it’s dangerous to do so. We should be immaculate in these respects. Murder is murder. This is a heinous crime. Thankfully it is an exceptional act in terms of the broad conduct of armed forces.
1. He did not call for the soldier to receive the harshest possible sentence, although he did express revulsion at the crime.
2. He noted that there was due legal process and it should be followed without interference.
3. He did not say that clemency should not be considered by the CM: 'you are not ruling out...the idea of clemency by judicial process?' gets the answer 'No'. Nowhere can it be said that he is calling for 'the maximum sentence' (it has to be life, because that is the sentence for murder - the issue is the tariff for time served, for which there is no maximum now that whole life tariffs have been effectively squashed by the European Court - which, before we get the usual input from the usual sources, is not part of the EU - so how could CDS be calling for 'the maximum'?
As for petitions, are we seriously in the position of saying that the public should, via Facebook, be able to influence decisions of a court? Whether one feels sympathy or not for Marine A, the idea that popular opinion should influence sentencing is - sorry - utterly bonkers.
It's also somewhat er... ironic that a poster putting a link to a petition - thus seeking to interfere with due process - condemns CDS for interfering in due process with his comments...