The BBC also has an article on that documentary. Barring any translation errors, what Putin said was a less obvious admission of the methods, at least those prior to the events...:
Mr Putin said on TV he had ordered work on "returning Crimea" to begin at an all-night meeting on 22 February. [...]
"I invited the leaders of our special services and the defence ministry to the Kremlin and set them the task of saving the life of the president of Ukraine, who would simply have been liquidated," he said.
"We finished about seven in the morning. When we were parting, I told all my colleagues, 'We are forced to begin the work to bring Crimea back into Russia'."
[...]
Mr Putin subsequently admitted deploying troops on the peninsula to "stand behind Crimea's self-defence forces".
RFERL has an article (and a video with English subtitles) on the Putin comments, the most clear part about the "little green men" being:
"In order to block and disarm 20,000 well-armed [Ukrainian soldiers], you need a specific set of personnel. And not just in numbers, but with skill. We needed specialists who know how to do it," Putin said in the documentary.
"That’s why I gave orders to the Defense Ministry -- why hide it? -- to deploy special forces of the GRU (military intelligence) as well as marines and commandos there under the guise of reinforcing security for our military facilities in Crimea," Putin added.
There is a bit of a time gap between these orders/discussion on the 22nd and the obvious appearance of the "little green men" on the ground in Ukraine, at least in terms of obvious actions, like seizing airports and the local parliament/assembly, all of which took place in the night of 27 Feb and the day of 28. But some of their movements were traced as early as Feb 25, e.g. the arrival of Nikolay Filchenkov in Sevastopol likely with Spetsnaz/KSO on board. (Interestingly, Feb 27 was later decreed by Putin to be KSO day.)
