I think there's an argument there that separates the religious aspect from the moral aspect, as without the religious aspect of the zygote having a soul, it is unquestionably just a bunch of cells, and completely devoid of any form of consciousness. I also think there is room in a reasonable debate for the religious to find points where they may concede that pressing their values upon others is a step to far, despite even deeply held beliefs to the contrary.
The reality is the whole debate around abortion gets more controversial the further along a pregnancy becomes, because as the fetus develops, it becomes less of a fetus, and more of human being, so I think that people can be entirely consistent in having an anti abortion stance, yet accept a termination of pregnancy at such an early stage of development.
Just as you can find pro choice advocates getting less confident or even abandoning support in the last trimester for example. I mean technically the difference between abortion and infanticide can be defined by whether or not a baby has been delivered, and I doubt very much you would describe a pro choice individual being against the idea of termination of a pregnancy a mere day before the birth is due, as having "abandoned a core value".
This is often the problem when we hear cries of hypocrisy based upon black and white determinations of an ethical or moral stance, there simply is no allowance for nuance, which is rather unfortunate.