In almost all cases, forward slash, '/' works like '\'.
That's pushing it. It's true in Perl (since the Windows API accepts "/"), but not so much in the shell (because "/" is the command line option starter, and it doesn't need to be preceded by whitespace). For example, dir /users won't work.
That said, if you place the path in quotes, "/" is much more likely to get accepted. For example, dir "/users" does work.
This is only relevant if $pathSeparator is used to build shell commands, which is possible. It's hard to tell, since $pathSeparator isn't actually used in the posted snippet.