Now the punchline. The whole point of quantum teleportation is that collapsing a particle's wavefunction will also collapse the wavefunction of a remote, entangled particle. Will that destroy the remote particle's self-interference fringes? If so, then we have our ansible.
The idea is to conduct some random event, say 1,000 coin tosses, and pre-commit to cancel the LHC if we observe a ridiculous outcome, like 1,000 heads in a row.