"The woman and the man are alive."
Translation:Femeia și bărbatul sunt vii.
Hard to argue for it but I think it is because the emphasis may be on the fact that one is a female while another is a male. The usage of omul is pretty vague, similar to how man can be in English.
If you wouldn't need to put emphasis on the fact that one is female and another male, you wouldn't be saying the woman and the (vaguely) man are, you'd be saying the (vaguely) men are. Similarly in Romanian you could've said oamenii sunt instead of femeia și omul sunt but if you do want to put such emphasis, which I believe is intended, then it makes sense to use femeia și bărbatul.