I rewind if I miss something. Be it what was said, if there was something I didn't catch in the background, subtle clues. I've been known to rewind even after I've watched it before. Sometimes that second time around gives new insight into the whole series.
I will do that ofcourse but if I know what happened right away, I wouldn't bother going back again to verify it. There are many anime which got fast moves and they would be explained later.