I spotted this story at the time and was frankly baffled. The BBC has a short post-court report:http://www.bbc.co.uk/news/uk-england-32114878

Today via a policing blogger is the officer's own explanation for his PTSD, dating back to service in the army in Iraq. In places it is rightly critical of his immediate supervisors and the personal impact of policing when budgets have been cut by 20%:https://beatstigma.wordpress.com/2015/04/09/about-me/