something even more important... they do not tap email. or they are stuborn as hell and took that personally.
think about it... what does it even matter that lavabit exists?!? email is plain text. they already have ATT and verizon in their bed. they could tap that plain text anywhere.
unless all the parties ever only used decent MX i think...
The original order wasn't for SSL keys or even Snowden's emails, it was for the envelope information and the IPs he was connecting from (see page 4 of http://cryptome.org/2013/10/lavabit-orders.pdf)
They wanted data on where Snowden was and who he was communicating with. Snowden uses PGP on top of Lavabit and presummably connecting to Lavabit securely. So at least to get his IP address, they needed Lavabit's cooperation or, baring that, the SSL keys.
It's a heavey handed approach, but not irrational.
think about it... what does it even matter that lavabit exists?!? email is plain text. they already have ATT and verizon in their bed. they could tap that plain text anywhere.
unless all the parties ever only used decent MX i think...