There's no reason why the first thing the facehugger does is extend the ovipositor. A better strategy would be to clamp onto the host with its legs, and then wrap the tail around the neck to constrict the arteries leading to the brain. Eventually the host falls unconscious, then the ovipositor does its thing, injecting an egg plus some toxin that makes the host remain immobile long enough for the larva to settle in and start growing.

There's no reason why the first thing that the facehugger does has to be to extend the ovipositor. A better strategy would be to clamp onto the host with its legs, and then wrap the tail around the neck to constrict the arteries leading to the brain. Eventually the host falls unconscious, then the ovipositor does its thing, injecting an egg plus some toxin that makes the host remain immobile long enough for the larva to settle in and start growing.