I don't think any words were put into his mouth, seeing as how he actually said it. Regardless of what was meant to be said, it was said. I understand that he meant to make a jab at our Commander in Chief (which in my opinion is just as bad) but the point is it isn't OK to say things like that. It's just like when George Allen called that guy a Macacca. It was a joke, but it was still offensive and he's still receiving backlash for it which could hurt him in the midterm elections and in the presidential election.
Furthermore Kerry's intended remarks were just as unfounded. Bush was a veteran as well, not to mention Kerry's schoolmate. Bush was educated at one of the most prestigious high schools in the world, and at the top two colleges in the country (Yale and later Harvard, which he switched to for grad school as Yale was too liberal for his liking.) And even past that, Kerry has no room to talk as he performed worse in school than Bush.