It bugs me that the ox is dead. Doesn't the host need to be alive? What killed the ox before the chestbursting? Did it die because the alien started ripping through, but didn't fully emerge until they got it inside? Did the embryo stay in the body because it had some issue with the exterior atmosphere on the planet, or maybe the lice? Did the facehugger kill the ox when it was implanting the embryo? Did it die from some other side effect of the embryo?
It's also frustrating that only one cut of the film introduces the concept of the queen facehugger. Granted, it's brief & subtle, but seems like a pretty big piece of lore that will eventually need to be confirmed or contradicted by a future movie.