Im not sure how this distinction applies in this case since in each iteration the government was trying to obtain their legally subpoenaed data in the most specific way possible.
They were not able to decrypt the data without the account password, which can only be derived using Snowdens personal password, so that poses a problem. To get the password they were forced to demand that Lavabit hand over private SSL keys (so they could potentially intercept the password in transit over the network). Now the courts have to decide whether such an act is legal or if it constitutes a violation of the 4th amendment (and possibly free speech). Should be interesting to see how this pans out.
