4th edition D&D: Does “phasing” away from 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. If a power allows a creature to become insubstanial (hits do only half damage) and move via of "phasing", according to the rules, that creature is able to move through an opponent's space. There is no specification that an attack of opportunity can not be taken. My thought is that the creature can be attacked because it is leaving it's adjacent space moving through an opponent's space and taking a position on the opposite side of the opponent in a different adjacent space. If someone knows of a sanctioned ruling that would be great! Thanks.

Answer 1

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.

Answer 2

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. :)