Accept then decline single occurence

[yfnitg]

Outlook 2003/Exchange 2003. Organizer sends a recurring weekly meeting
request to 1 person. Invitee accepts. Later, invitee clicks on the meeting
in his calender, opens one occurence, and declines.
Invitee still shows up as accepted in organizer calender for that occurence.
Is this by design?...if so, how and why? If not, what is not working
correctly?

Thanks
yfnitg