Unwilling Targets: Sometimes rituals are cast on unwilling recipients. The player of an unwilling recipient may inform the ritual marshal that he or she wishes her character to resurrect rather than accept the ritual. In the case of ritual effects delivered outside the context of a ritual casting, the player may choose to have their character immediately dissipate and head to the nearest earth circle for ressurection, following the normal rules.
Note: In my experience when a player refuses a ritual, IG it is often rationalized as "the magic didn't work" similar to a random backlash. Other rationalizations include "the magic didn't accept me", "my Spirit is too strong for that magic", "the fey/elementals/cursed/dragon/etc. protected me", and "the caster made a mistake in the casting".
In general, any rationale can be used as to why the ritual didn't work. Since the book clearly states the choice to refuse is an OOG decision it is recommended that whatever rationale is created removes any opportunity for character choice.