[tor-talk] How FBI Pinpointed Silk Road's Server

[Jim]

Wired has recently published an article about how the FBI claims to have
found Silk Road's server:

http://www.wired.com/2014/09/the-fbi-finally-says-how-it-legally-pinpointed-silk-roads-server/

The FBI claims:

"As they typed 'miscellaneous' strings of characters into the login
page's entry fields, Tarbell writes that they noticed an IP address
associated with some data returned by the site didn't match any known
Tor 'nodes,' the computers that bounce information through Tor's
anonymity network to obscure its true source."

I don't see how that is possible, regardless how badly misconfigured the
server is.  When the server is accessed as a Tor hidden service it
doesn't know the client's IP address.  So the only way it can respond is
back through Tor.  Unless by "typing miscellaneous strings" they managed
to infect the server with something that contacted an FBI machine via
clearnet, similar to Magneto.  Am I missing something?  Or are they
stretching the meaning of "typing miscellaneous strings"?  Or outright
lying?

Jim