Well...it did happen, and they aren't in my contact list, so I guess it must be possible to some extent, because I didn't imagine it.
I checked my contact list several times before coming to the conclusion that I still didn't know that person and had never added them before, so even if it were an error of ignorance, I am almost positive I'd have caught it. I've just checked it again, and still, nothing.
I'll pull up the log history as further proof if I must.
If it's that hard to believe, I'll even screenshot my contact list in the various ways one can explore it, but I'd rather not go through the trouble and just hope someone's either going to tell me to do something I haven't done before, or that they'll recognize the problem and have an explaination. But anyway, here's the bit of the log that's relevant:
fashion-guess@hotmail.com (fashion-guess@hotmail.com)
Date: 2008-06-10 - Time: 06:04:33
Signed In (Online)
fashion-guess@hotmail.com (fashion-guess@hotmail.com)
Date: 2008-06-10 - Time: 06:04:34
Name changed: Laetii. || ..L&J
<== Je T'aiime x'
Laetii. || ..L&J
<== Je T'aiime x' (fashion-guess@hotmail.com)
Date: 2008-06-10 - Time: 06:04:34
Personal Message changed: Chériie Coco Just Want To Be A Fshn Girl.x THIRSTY ME :: ' Jiihane, ILove You Bestiinaa ' Cousiinaa
Laetii. || ..L&J
<== Je T'aiime x' (fashion-guess@hotmail.com)
Date: 2008-06-10 - Time: 06:04:46
Signed Out
Like I said, I have checked the contact list time and time again, and unless I've become totally inept at finding people, this person never has been and, likely, never will be on my list. Allowed or disallowed.