This does not appear to be a swiftboating tactic, they are asking him for his rebuttal, and say they will "stand down" if he can justify himself.

McCain has, apparently, had no argument other than an appeal to authority?

McCain's argument appears to be that the Senate has had access to all classified documents, has sent people to Vietnam, and has resolved the issue to the greatest extent possible.

Some people whose loved ones did not come back from Vietnam will NEVER be satisfied, because the bodies were lost in the jungle or otherwise destroyed. I feel for them...but like John McCain, I realize that closure on the issue of their loved ones' fates will be impossible for some people in this lifetime.

This woman has a lot of gall suggesting that McCain and the rest of the government don't care about POW/MIAs - for God's sake, McCain was a POW for 5 years! He wouldn't leave anyone behind who, in his estimation, could possibly be found.