The trial of a former Civil Aviation Authority safety manager on charges of forgery and attempting to pervert the course of justice is entering its final stages in Wellington District Court.
Peter Kirker told police he saw himself as a whistle blower when he sent the email at the centre of the allegations.
The email, which purported to be from Frank Sharpe, an aviation expert, was presented to an inquest into the deaths of three men in a mid-air collision over Paraparaumu in 2008.
A subsequent police inquiry revealed Mr Kirker had sent the email.
Lawyers for both sides presented their closing submissions on THursday morning and Judge Andrew Becroft is expected to give a decision later in the day.