Let's play spot the differences

Canada's Chief of Defence Staff, Gen Rick Hillier, announced his retirement yesterday. Some conflict about the announcements that came through by email today:

From the CDS' email to all DND and the CF (emphasis added):

"I have chosen to retire from the Canadian Forces and end my tenure as your Chief of the Defence Staff in July of this year. [...] I will continue to serve as your CDS until relieved of my duties by my successor, to be named in due course by our Prime Minister."

From the Prime Minister's [propaganda] Office (emphasis added):

"Prime Minister Stephen Harper issued the following statement on the planned retirement of General Rick Hillier as Chief of the Defence Staff:"

What's wrong with this? On the one hand, we have a surprise announcement (as far as timing goes, anyway) from the CDS, saying he has "chosen" to retire. On the other hand, we have the PM's communications office saying it was a "planned" retirement. But, if it was planned (at least by the PM's office), and the PM is responsible for naming the successor, shouldn't they already know who the successor will be? I suspect this is yet another example of the PMO (Propaganda Minister's Office) trying to colour the facts in their favour.