By default Simpletest removing all Verbose messages, so it's not possible to read them

After running any test, during DrupalWebTestCase->tearDown() the whole folder 'simpletest' is removed which contains generated verbose messages (html files). So it's not possible to click on them and see the verbose message on the Result page (right after test was run), which is ending with Page not found.
File: drupal_web_test_case.php

  protected function tearDown() {
...

    // Delete temporary files directory.
    simpletest_file_unmanaged_delete_recursive($this->originalFileDirectory . '/simpletest/' . substr($this->databasePrefix, 10));

    // Remove all prefixed tables (all the tables in the schema).
    simpletest_clean_database();

xdebug:

-> SimpleTestCloneTestCase->tearDown()
-> DrupalWebTestCase->tearDown() 
...
-> simpletest_file_unmanaged_delete_recursive($path = 'files/simpletest/') modules/simpletest/drupal_web_test_case.php:1372
...
$entry_path = 'files/simpletest//verbose' modules/simpletest/simpletest.module:572
...
simpletest_file_unmanaged_delete_recursive($path = 'files/simpletest//verbose/ULegal-1.html') modules/simpletest/simpletest.module:573
...
rmdir('files/simpletest//verbose') modules/simpletest/simpletest.module:576

I assume it happens as well in Drupal 7, because I didn't see any difference in the code. If not, I'm not sure if I understand how exactly it should work.