Whisper in the Dark overrides that rule since it specifically allows a follower to bear it.
Bit off-topic, but this reminds me of the debate over whether
O Elbereth! Gilthoniel! allowed the Ring-bearer to cancel his skirmish (after the no-cancel rule was newly minted). IIRC the official stance was that LotR has no "Golden Rule" about cards overriding the rules. (So basically since O E! G! was printed before,
obviously it wasn't supposed to work--but if it was printed after, it'd obviously be meant to?) The rulebook maintains "As skirmishes involving the Ring-bearer cannot be canceled..." as its reasoning, but eh... generally cards > rules.
