Actually, he's right. This is sheer luck. "multipart" is a tag used in mail gateways to describe a MIME message (it's used to split the message file in different parts, the one with text only, the binary file for attachment, the html part...etc).
EXAMPLE :
This is a multi-part message in MIME format.
------=_NextPart_000_008F_01C1B2E4.5C8BADB0
Content-Type: multipart/alternative;
boundary="----=_NextPart_001_0090_01C1B2E4.5C8BADB0"
------=_NextPart_001_0090_01C1B2E4.5C8BADB0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
------=_NextPart_001_0090_01C1B2E4.5C8BADB0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
------=_NextPart_001_0090_01C1B2E4.5C8BADB0--
------=_NextPart_000_008F_01C1B2E4.5C8BADB0
content-type: application/pdf; name="NetCost-93-20020208.pdf"
Content-Transfer-Encoding: base64
content-disposition: attachment; filename="FUBAR.pdf"
So, it IS really luck

A bug from microsoft OWA which renames attached messages.
Now, what is the real part in the name which triggers the cheat? Could anyone test this out? I'm at work ... Maybe it's just the name "multi" in the saved game (somehow an embryonic multiplayer mode testing?)
loki