Talk about a bug that took me an hour to fix. Changing

{ return $main::VARIABLE{$item{VARIABLE}} }
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to

{ $return = $main::VARIABLE{$item{VARIABLE}} }
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does the trick. For completeness, I would change the other two return FOO to $return = FOO also.

I think you should write to the author of that tutorial and give him a heads-up. Also, this is off-topic, but the line /\w[a-z0-9_]*/i isn't quite right. Indeed, /\w/ is /[a-z0-9_]/i, so what is probably intended is /[a-z]\w*/i. In this case, it makes little difference (the former allows variables beginning with underscore), but if some code is rearranged then errors might pop up.