Yea, those memories are something else.

The yelling is all part of the program to motivate you to go to your limit and beyond, to stop thinking and acting like a civilian. The DI wanted him to sound off as he said, short, sharp and fast (everything you say in boot camp is that way) and he wanted to know why he didn't go through the course. The kid was one of the lame and lazies it sounded like to me, he was claiming to be dehydrated and then to top it all off, once the course was completed he told the corpsman he was feeling better. So in essence, he played sick so he wouldn't have to crawl around in the mud in the infil course, then magically said he was doing better when his group was through.
The kid was playing games to try to get over, if he was a real heat/hydration casualty he would have been tended too and wouldn't have gotten his butt chewed. He wasn't so the two DI's go all over him, he's not putting out up to the standards. I would have loved to see what happened to him off camera, later that night or the next day he was probably PT'd to death. lol