#get rid of the bad doct characteres
if ($ARRGH =~ /<className>ibZtfacr008_chg<\/className>/) {
    $ARRGH =~ s/<doct>Customer trans\.(.*)<\/doct>/<doct>Customer trans\.<\/doct>/g;
}

##</code><code>##

<event>
  <className>ibZtfacr008_chg</className>
  <oldvalue>
    <x>foo</x>
    <y>bar</y>
    <doct>Customer trans. garbage</doct>
  </oldvalue>
  <newvalue>
    <x>bar</x>
    <y>foo</y>
    <doct>Customer trans. garbage</doct>
  </newvalue>
</event>