He attended at times. He was a representative of UK and even if he failed to attend, he was preventing the place being taken by an EU sycophant. As such he was serving a purpose. But when he did attend he was routinely reviled, so I quite understand his choosing his times to attend.
As to what he 'earned', the EU was paying all the EMP irrespective. I don't believe he was just doing it to play the system, but even if he was then that could be blamed on the laxity of the EU's own rules. At least he knew there was a chance of the payments being audited, admittedly the chance was 'slim to none'.