Spike tells Fred that, when he disappears to what seems to be Hell, something takes hold of him and appears to be trying to keep him there.
Now, how would that sensation differ from something or someone grasping hold of him in order to be pulled out of Hell when he returns to normal existence?
Who gave Angel the amulet responsible for Spike's condition?
Who is trapped in Hell and stuck there because the Senior Partners are too cheap to pay the power bill?
Who assumed that Angel would be using the amulet and has no great love of Angel and a whimsical sense of humour?
Is the vampire with a soul Lilah's escape route? And is the problem the simple fact that Spike is so much less massive than Angel that it is harder for him inadvertently to drag her back?
Probably not, but it would be an inventive spin on the whole harrowing Hell thing.