To reproduce:
Error 400: Invalid request will appear at the top of the page along with PHP error:
Fatal error: Class 'JToolBarHelper' not found in /path/to/joomla/administrator/components/com_patchtester/views/pulls/view.html.php on line 119
Checking the patched files administrator/includes/toolbar.php and administrator/includes/subtoolbar.php both contain the 400 text.
Yep, I get the same result for the issue