Abyssal Rift's plane shifting qu

[Particle_Man]

The spell Abyssal Rift (in Fiendish Codex I) gives victims reflex saves to avoid falling in the rift and to avoid the fiery tentacles. Also, "anything still trapped inside the rift when it closes plane shifts (as the spell) to a random layer of the Abyss". So do trapped beings get a will save? Does spell resistance apply? Or are they simply plane shifted? The line for Abyssal Rift says: Reflex negates; see text.

 

[Dandu]

I can see SR applying, but the will save is a bit ambiguous. Not sure if they meant the creature transitions to a plane as if via Plane Shift, or suffers the effect of the Plane Shift spell, complete with the will save.