If someone sneezes and doesn't say "Alhamdulillah," am I permitted to remind him?

Sneezing upon someone is prescribed for those who sneeze and praise Allah. As for those who do not praise Allah, they should not be sneezed upon, nor should they be reminded to praise Him. This is because two men sneezed in the presence of the Prophet, peace and blessings be upon him, and he sneezed upon one of them but not the other. When he was asked about that, he said: "This one praised Allah, and you did not praise Him." If reminding them were permissible, the Prophet, peace and blessings be upon him, would have reminded him.