Try it out with the following XML:
<?xml version="1.0" encoding="UTF-8"?>
<testsuites>
<testsuite name="DataTest" file="/home/sb/DataTest.php" tests="4"
failures="1" errors="0" time="0.004322">
<testcase name="testAdd" class="DataTest" file="/home/sb/DataTest.php"
line="17" time="0.001042"/>
<testcase name="testAdd" class="DataTest" file="/home/sb/DataTest.php"
line="17" time="0.001529"/>
<testcase name="testAdd" class="DataTest" file="/home/sb/DataTest.php"
line="17" time="0.000571"/>
<testcase name="testAdd" class="DataTest" file="/home/sb/DataTest.php"
line="17" time="0.001180">
<failure
type="PHPUnit_Framework_ExpectationFailedException"><![CDATA[testAdd(DataTest)
with data set #3 (1, 1, 3)
Failed asserting that <integer:2> matches expected value <integer:3>.
/home/sb/DataTest.php:19
]]></failure>
</testcase>
</testsuite>
</testsuites>
If you use the phpunitreport task on XML like this, the HTML output will not include detail about the testAdd method. No failure message, no backtrace, etc. This isn't because the test failed - the detail is missing for passing tests too - but I noticed it with failing tests because that's when you need the detail ;)
I'm attaching a screenshot to better explain what I mean.