It's curious / ironic that Fr. Chazal would write in English only to have it translated back into French.
Not really in so much as he presumably wanted to get an English edition out first to a bigger potential market. In any event, feel free to inquire of him. Fr. Chazal is Fr. Chazal.
I was very happy to read the first sentence of his preface to this book: "Dear Reader, after this book on eternal death, I shall write another one on eternal life called
Eternal Crown, the two of which will be called
Eternity, because "man shall go into the house of his eternity" (Eccles.12:5).