The dilemma has three steps:
1. Assume that God must do what is best for every servant.
2. Explain the youngest brother's early death as protection from a future of sin and punishment.
3. Let the disobedient brother ask why the same protection was not provided for him.
The difficulty appears in the third step. If the first claim is universal, applying the protective reasoning to one person but not the other requires a further explanation.
In the transmitted exchange this is presented as a difficulty for al-Jubbāʾī. Understanding the logic of that reported reply is not the same as proving that no later or different Muʿtazilī response could be offered. The lesson evaluates the argument as it is presented here.