I expected this function to return FALSE or 0 if a symbolic link did not exist (per the documentation above), but that's not what happened. Reading the man page for the Linux kerne's stat call here: http://www.kernel.org/doc/man-pages/online/pages/man2/stat.2.html it says this:
RETURN VALUE - On success, zero is returned. On error, -1 is returned, and errno is set appropriately.
... which is what is happening in my case. I am doing a linkinfo('/path/to/file'); on a missing symlink, and I get back a value of -1. As we know, a value of -1 is not going to evaluate to a FALSE or 0.
My point - be careful with return values for missing symlinks.