It's not (just) environmental.

>dir /b \\tribble05\c$\*
AUTOEXEC.BAT
...

>perl -le"print for glob shift" \\tribble05\c$\*

>perl -le"print for glob shift" c:\*
c:\AUTOEXEC.BAT
...

>perl -le"opendir $dh, shift; print for readdir $dh" \\tribble05\c$
AUTOEXEC.BAT
...
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