There are plenty of issues with John McCain's story. A quick internet search comes up with plenty of sites that highlight the problems:

http://www.truthdig.com/report/item/20081007_investigating_john_mccains_tragedy_at_sea

https://www.youtube.com/watch?v=pIWeq2DL_N4

The allegation is that McCain wet-started his plane and accidentally fired off the Zuni missile in the first place. Furthermore, it wasn't that missile that caused all the deaths, but the damage caused when the fire spread to McCain's plane and all his ordnance went off. Had he just piloted the plane off into the drink, he would have died but none of those explosions would have happened.

You can call it "idiocy" but the fact that many of the survivors of the fire came to the same conclusion as the people in the documentary tells me that it's not as "idiotic" as you say.

For the record, I've never liked McCain since the 2000 Republican primaries. His stance on Russia is one more reason not to like him, but the list of obnoxious things he's done that have hurt the Republican Party put him on a par with Donald Trump in my mind (or even worse than Trump, since he actually spitefully lost the 2008 Election in part by choosing Sarah Palin, the only person or thing mentioned so far that merits the badge of "idiotic" in this post). In fact, his anti-Russian stance is just one small facet of reasons to not like McCain.

I will only credit John McCain with ONE good action in his entire life: when he was in the Hanoi Hilton, he refused to be released if his fellow POWs weren't released along with him. That one action took courage, fortitude and perseverance. However, it doesn't justify everything else he's done or give him a free pass on his pettiness, war-mongering or terrible decision-making.