"Hello Edward, I am a Russian diplomat, come to Moscow and we won't extradite you to the Americans"
"Hello Edward, I am a Russian spy, come to Moscow and we won't extradite you to the Americans"
I can't imagine Snowden was under any illusions about the job title of the "diplomats" he was talking to, so it wasn't much of a trick. It might not have been a particularly good long term deal, but there wasn't a whole lot else on the table.
It seemed pretty clear in reading Greenwald's book that Snowden had no illusions about anything he did or the consequences. He never attempted conceal his activities or obscure his own person. He knew that due to US policies he would be charged with treason and found guilty. His only hope was that he could avoid extradition and not spend the rest of his life in a 10x10 wet hole in gitmo. Whatever rumors swirl around him mean nothing so long as he can stay out of prison until America changes his policies, or he can get on a rocket to Mars. The latter is probably more likely to happen sooner than the former.