As in all matters of "wrongdoing", repentence or the lack of it is key.
In all matters such as $exual immorality except bt, most of the time the verdict is unrepentant followed by df. The key in bt is that the sinner doesn’t show defiance or says that wt is wrong about the doctrine, for example. If that is the case then obviously the sinner doesn’t want to be a JW and is disassociated as you pointed out. Other than that, if the sinner says he was afraid or gives some other reason why, admitting his guilt, that is sufficient evidence of repentance to the tribunal . WT won’t test the truthfulness of his words as is the case with other sins. Obviously, a JW will refuse a bt if he can help it but under the pressure of the moment he might give in, so prima facie the case is about weakness and much mercy and compassion and understanding is extended and usually it is the sinner that feels very bad about it. But it the sinner starts carrying on that the wt is wrong or justifies what he did, it becomes clear he is not a JW because JW believe and practice different.