Nicholas Clarke QC said:
In his outstretched hand was a gun. The gun was fired. Mark Short was nearest to the door when the gunman came in.
Mark Short fell to the ground as the firing continued, focused on the people stood around a pool table.
Three more men, John Collins, Michael Belcher and Ryan Pridding, were also hit and fell to the floor.
After firing seven shots in quick succession, the gunman left through the door that he had entered and jumped back into the front passenger seat of the waiting Ford Focus.
More top news
UK defence secretary says so-called Islamic State group will only be defeated by force.
Sheriff's deputies were called to the scene in LA County after residents reported hearing muffled crying.
Further one in eight expect to be aged between 71 and 80 years when they finally stop work, according to survey.