The namesake of this episode is the "Falx Cerebri", a part of the dura mater in the brain. It is known for being in the shape of a scythe. The Grim Reaper on the MC jackets is holding a sycthe. Also, Chibs (Tommy Flanagan) suffers a head injury in this episode. The name of this episode alludes to both.
Opie says Jax lost him at Corcoran Pass. This likely references producer Kevin Corcoran.