If I connect via SMB from my Mac, I can only see the user's home folder ... but if a Linux user connects via SMB, they can see everything on the whole machine.
So it seems that Panther's SMB server incorrectly shares the whole
machine, and its SMB client doesn't work the way other clients do and
fails to alert you to this problem.
[robg adds: I can't test this one here; if anyone can confirm, this sounds like at least a bit of a security hole...]