The two men were shot by two men wearing Afghan police uniforms.
The inquest heard an intelligence report that said "insider threat" was difficult to detect. Insurgents and the Taliban used this kind of attack as a tactic and there had been no increase in this kind of threat.
More top news
EE and Vodafone have bought a number of Phones4u stores in the Midlands after the Staffordshire firm went in to administration last week.
It will be dry this evening and tonight with clear spells and light winds.
Dry with clear spells and light winds overnight, so becoming chilly once again with a rural grass frost possible.