No summary executions?

Pedantic to say the least. A British court martial is still to this day of concern due to the inbuilt presumption of guilt and often biased military mindset in the judgement phase.

(Source - Amnesty International.)

Considering executions in WW1 were set up as a deterrent, the word summary is rather appropriate. Not that officers make good judgement over the lies of soldiers. If they did, they wouldn't try to win by sending waves of men over the top once they found it didn't fucking work...