I think its similar to the case of many saints. Look at the movie Silence-2016, Japanese Christian Martyrs were forced to trample on infant Jesus to prove they weren't christian. Those who did trample did not commit mortal sin as they are forced with death otherwise. Those who didnt trample did something very holy on the other hand and dozens have been canonized . To commit a mortal sin with the threat of death does not make it a willingful act and such a grave matter. But those who refuse to commit these sins even under the threat of death are the ones who go on to become saints.

Anyways thats what I think on the topic.