My server was dropping the connection after EHLO because they were connecting from a different IP address and specified -all in the SPF record. Maybe you are seeing a different issue.
He's entering "fastmail.com" into the form on the web site then the EFF's server is trying to connect to (at least one of) FastMail's MX hosts but is unable to establish a connection.
As OP said, what he is seeing has nothing to do with SPF.
(Side note: I'm a mail admin and I'm pretty strict, but even I don't drop anyone after HELO/EHLO. I'm not surprised you're having issues.)