Otherwise the collision creates debris that the Earth immediately flies through, or wil fly through about a year later.

Not necessarily. An object that would shatter the Moon would do just that, shatter it. This does not mean that the separated bits would necessarily go anywhere. The energy of impact would go into the shattering process and would therefore not move the bits into a significantly different orbit. We may end up with a ring, or if there are sufficiently big bits left, they may reform into a 'new' moon.