The BBC indicates they got 50% rather than 35%:
http://www.bbc.co.uk/news/election/2015/results/scotland
That said, a good deal* of 'no' voters voted SNP this time because people seem to be sick of the growing disconnect between the electorate and those chosen to represent them. I agree that secession isn't realistically on the cards though.
* for a given value of 'good deal'