We don't know what kind of automatic weapon was used. However, an M16 has a range of at least 1,500 feet. So, yes, the shooters could have concealed themselves in the bushes and still peppered their target with quite a few bullets in just seconds. I still say that Michael saw the muzzle flash which keyed his reaction. Of course, he could have seen some movement of the shooters too.

But Apple's right (here I go again). The movie had to continue, so Michael avoids the hit.