This is no joke, the CPU blitzes a ton. It's what makes the game so easy, I think.
It's only part of the reason we see so many hits in the backfield, though. Line stunts are a huge part of it, and line stunts are in a lot of EA's defensive plays. More than they should be, imo. Someone in the impressions that posted the really good idea of splitting the defensive plays into their respective parts. It would not only greatly expand that side of the ball, but do away with some of these things.
The problem is, unless you play on very low run settings, the AI has a hard time picking stungs up. The DE is in the backfield before you know it. There are ways around that, the most successful being not running left.