Ed famously quoted Dylan Thomas: "Do not go gentle into that good night -- rage, rage against the dying of the light!" In his classes he emphasized the importance of staying in the fight, focusing on the task, and getting the job done.
He told me one of his strongest memories of the gunfight was focusing on his front sight for each of the eleven shots he fired, seeing the bead of his 870 shotgun as a huge ball and the giant colored insert on the front sight of his S&W 686 as he finished the gun battle.
Ed pointed out that things stored in the car, from long guns to boxes of spare ammo, are unlikely to be employed when the fight goes dynamic, and what you have on your person is all you'll be able to absolutely count on having.
As soon as allowed after he went back on duty, he switched from the revolver to the SIG P220 .45 auto, and received permission to use a privately-owned, Bureau approved Benelli Super 90 semiautomatic shotgun.