Meeting request is responded to by out of office request -shared c

[Jeff Lowenstein]

Here's the issue:
Mark has given Marco editor rights to his calendar. Wendy sent Mark a
meeting request - Marco was not on the meeting request. Wendy received an
out of office response from Marco in response to this meeting request. Why
would Marco repond to a meeting request not sent to him? All are using
Office 2003 SP 2.