I'm sure there are legal cases to be made on both sides of this claim. But the fact that Snowden fled to Hong Kong to avoid the consequences of his law breaking - more than anything else - disqualifies him from claiming that mantle.
Take a look at how the Rev. Martin Luther King, Jr. described his understanding of civil disobedience after careful study in his Letter from Birmingham Jail (the title of which should be a give-away).
One who breaks an unjust law must do so openly, lovingly, and with a willingness to accept the penalty. I submit that an individual who breaks a law that conscience tells him is unjust, and who willingly accepts the penalty of imprisonment in order to arouse the conscience of the community over its injustice, is in reality expressing the highest respect for law.There are many things that can be said about Snowden's actions. But its clear that they cannot be put in the company of those who actually practiced civil disobedience.