The government were, understandably, a bit disappointed, and so nine months later, twenty months after the action, they engineered a second trial in a lower court, without a jury. In English law you can’t be tried twice for the same crime without additional evidence, and there wasn’t any, and so the CPS had to charge them with a different offence, namely aggravated trespass.

The government had gone some way towards appealing the original case to the Court of Appeal, but abandoned that effort because they had a lower chance of victory than the other route of bringing rather vague new charges in front of a court without a jury. Less satisfying for them, as the original verdict remains unchallenged, but less likely to backfire.

The ‘lawful excuse’ defence isn’t available as a response to this charge, as it is specific to criminal damage. The six decided not to engage counsel for this case, as they had already proven their point in a higher court, and so there was nothing to be gained from going through the same process again in a lower court without a jury.

So, whilst you are quite correct that the six were convicted of aggravated trespass, the presiding magistrate actually didn’t hear the ‘lawful excuse’ defence.

There’s an interesting civil liberties issue here, with the removal of the right to trial by jury allowing the government to pursue people through the courts in a rather petty and vindictive manner, but it’s not really a Greenpeace issue, and so we haven’t made any effort to publicise it.