Can Mighty Eagle not achieve completion of a game board?

I haven't purchased the Mighty Eagle but am curious if it's possible to throw the sardine tin in a spot in which the Mighty Eagle will not achieve completion of a board? Or does the sheer force of the eagle hitting inside or outside the game-play area always cause all pigs to be destroyed? I noticed the ground bounces.

Videos, which are my only source of information at this point, show how the Mighty Eagle destroys mostly everything on the first use but sometimes with a bit of structural integrity left behind, like some bits and pieces on the ground.

I expect the answer to this question will be short. :)

Yes, the Mighty Eagle kills all the pigs in the level, even if you throw it backwards off the screen. However, the eagle will not destroy all the blocks on the screen, as you said.

The Mighty Eagle is kind of like a mini game within Angry Birds that passes the level for you that you can only use every hour.

Source: I just tried it out on my iTouch.