On Tue, 19 Feb 2013 03:09:28 -0800 (PST), wrote:

A satellite of a closely approaching asteroid could be moving in any
direction relative to the Earth. However, 2012 DA14 was several
hundred thousand kilometers away from the meteoroid, orders of
magnitude more than the typical distance of an asteroid moon.
Asteroid 2012 DA14 was very small, with a very low escape velocity.

A fragment of DA14 could be very far away from it (the existence of a
fragment is much more likely than of a satellite). But it would still
be in the same orbit as DA14, and therefore couldn't have produced the
Russian fireball.