Ashley Davis

Answer: You could probably make a compelling argument that, as an alien-hybrid, Sil is stronger than a normal person and thus was just able to forcibly cut through the finger with the pruners by "crushing" it. Also, this is where good old suspension of disbelief comes in. The pruners might realistically have broken at some point, but it's a movie, so we can "forgive" this bit of unrealism because it creates a compelling scene.

TedStixon