وَلَا نُكَفِّرُ أَحَدًا مِنْ أَهْلِ الْقِبْلَةِ بِذَنْبٍ مَا لَمْ يَسْتَحِلَّهُ
We do not declare anyone of the qibla an unbeliever merely for committing a sin, unless the person deems it lawful.
Committing an offence and regarding a prohibited act as religiously permissible are different matters. Even a grave sin does not automatically cancel a Muslim's faith.
Istihlal, declaring an established prohibition permissible, raises a separate question that must be distinguished from the act of committing a sin without affirming its lawfulness.