I would challenge you to prove that there is no one else who could do the job. That is an easy excuse that we hear too often. Tell me why French is the skill that should be at the bottom of the list while other skills are at the top of the list.
Other skills have to be taken into consideration. Why not consider a bilingual candidate who does not have some of the required skills, and ask them to acquire the missing skills and offer to train them to acquire those skills? Yet that is not what happens. In actuality, French always ends up at the bottom of the list, by default. We have to stop saying that a given candidate checks all the boxes except for French. We need to look at all their skills and stop putting French at the bottom of the list.