Intermittent test failure in testBulkImportUpdateExisting

I saw this test failure on a documentation-only patch that was tested yesterday:
http://qa.drupal.org/pifr/test/338758

The test failed in:

LocaleFileImportStatus.php, line 159
Drupal\locale\Tests\LocaleFileImportStatus->testBulkImportUpdateExisting()

The assertion that is failing is the last one in that test method:

   $file = $this->mockImportedPoFile($langcode, -1);
...
    $timestamp = db_query('SELECT timestamp FROM {locale_file} WHERE uri = :uri', array(':uri' => $file->uri))->fetchField();
    $this->assertEqual($timestamp, $file->original_timestamp, t('File is updated.'));

It's checking that some timestamps are exactly the same... that seems a bit suspicious. Is the test passing only when it happens to run fast enough so that the timestamp when $file is first created and the timestamp when it's added to the database are exactly the same, or when exactly one "tick" has passed in between?

Sometimes these intermittent failures are due to real issues in the test; sometimes due to server glitches... Anyway, I thought I'd file an issue.