Running on my machine with Perl 5.16.3 produces:

er,ackrl heP Just another
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Changing $|-- to --$| like so:

sub _{@_<2&&return print@_;my@a;push@{$a[--$|]},$_ for
@_;_(@$_)for@a};_ split//,"huroP cels,tetah Jen akrr";
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produces the required:

Just another Perl hacker,
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See also: Japhy explains where behaviour of --$| is documented.

Update: To further clarify this mysterious "flip-flop" behavior when $| is --'ed, but not when ++'ed, notice that running:

perl -le 'print --$| for 1..5'
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produces:

1
0
1
0
1
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while running:

perl -le 'print ++$| for 1..5'
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produces:

1
1
1
1
1
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BTW, this magical --$| flip-flop often produces the shortest Perl golf solutions when you need to flip-flop between two different values in a loop; for example, it was used in Re^2: Mini-Tutorial: Working with Odd/Even Elements and Spending Time on Saving Time [golf].