he said "boy some days i sure wish i was an ensign on the bridge of that destroyer again". i think he just means that life was a lot easier or less stressful and full of bullshit when he was just starting out in the navy than it is nowadays
mccain is hot garbage and the worst and i think the admiral was indeed taking a shot but in a more of a roundabout "this fucking sucks and i wish i didn't have to be here, on television, with you traitors, having to play nice" sort of way