This has nothing to do with Perl. You are using cmd's exit. And there's no reason to believe the shell command exit(1) is valid.

Correct usage:

>cmd /c "exit 1"

>echo %ERRORLEVEL%
1
[download]

Incorrect usage:

>cmd /c "exit(1)"

>echo %ERRORLEVEL%
0
[download]

I would have expected "is not recognized" or a syntax error. But whatever. Garbage in, garbage out.

What happens is that exit(1) is treated as equivalent to exit (1), and (1) is numified to zero.

>perl()
Can't open perl script "()": No such file or directory
[download]