Well then, were it is:

Script:

use strict;

my $bar = tie(*STDOUT, 'Bar');

print "Before\n";
test();
print "After\n";

untie(*STDOUT);

sub test {
        local(*STDOUT);

        my $foo = tie(*STDOUT, 'Foo');
        print "In medias res\n";
        untie(*STDOUT);
}

package Foo;

sub TIEHANDLE {
        my ($class) = @_;
        return bless({},$class);
}

sub PRINT {
        my ($self) = shift;
        print STDERR ("Foo::PRINT: ",@_);
}

package Bar;

sub TIEHANDLE {
        my ($class) = @_;
        return bless({},$class);
}

sub PRINT {
        my ($self) = shift;
        print STDERR ("Bar::PRINT: ",@_);
}

Output:

Bar::PRINT: Before
Foo::PRINT: In medias res
After

Expected output:

Bar::PRINT: Before
Foo::PRINT: In medias res
Bar::After

It seems like STDOUT is retied to Foo and then untied. local(*STDOUT) has no effect here. Why?