Does phasing away from an opponent provoke an attack of opportunity?

Question

I know the rules for opportunity attacks: the only way to avoid an attack of opportunity is to either shift away or teleport away.

However, if a creature moves via phasing, do they still trigger opportunity attacks?

Consider this scenario: if a creature becomes insubstantial (which means it takes half damage from attacks) and phases, then according to the rules it can move through an opponent's space - and thus it can move straight through an opponent to end up on their opposite side, on a different adjacent space. I think this triggers an opportunity attack, and I haven't found any mention that one cannot be taken.

Answer 1

Phasing is a mode of movement (it is listed under the heading of "Movement Related Traits") which allows a creature to

... ignore difficult terrain and ... enter squares containing blocking terrain, obstacles, and enemy creatures. The creature follows normal rules for where it must end its movement....

Rules Compendium p. 208

A phasing creature is still subject to opportunity attacks and other effects of moving; it only has the added ability to ignore difficult terrain and to move through spaces that aren't otherwise legal. If you had a character with phasing and shift 2, it could shift to the directly opposite side of a medium creature without provoking. Phasing would also let you use the normal shift 1 movement action even when you were on difficult terrain. It doesn't make you a ghost on the battlefield. :)

Answer 2

From the Rules Compendium pg 314:
While phasing, a creature ignores difficult terrain, and it can enter squares containing enemies, blocking terrain, or other obstacles. The creature follows the normal rules for where it must end its movement (normally an unoccupied space).

The rules for opportunity attacks are always stated pretty clearly so I would say that the 'phasing' character could be subject to an opportunity attack.