Surviving crewmen and those who investigated the Forrestal fire case reported that McCain deliberately 'wet-started' his A-4E Skyhawk to shake up the guy in the F-4 Phantom behind his A-4. 'Wet-starts', done either deliberately (the starter motor switch allowed kerosene to pool in the engine and give a wet start) or accidentally, shoot a large flame from the tail of the aircraft. In McCain's case, the 'wet-start' 'cooked off' and launched the M34 Zuni rocket from the rear F-4 that punctured the Skyhawk's fueltank, knocked the M-65 1000 lb bomb off it's 500 lb rated mount, and touched off the explosions and massive fire. The F-4 pilot was reportedly killed in the conflagration, along with 167 of his fellow Forrestal shipmates (including those who died later from wounds suffered). 'Wet starting' was a common practice among young 'hot-dog' pilots. McCain was quickly (they were still counting the Forrestal dead) transferred to the USS Oriskany (the only Forrestal crewman to be immediately transferred).
If you're going to make character an issue, better be sure you're not another privileged party boy who used familial connections to get you out of jams, or destroyed five tax payer provided jet fighters and had your attack dogs brand your opposition as unpatriotic.