I respectfully question the use of "Never."
I would suspect that he was a practicing Muslim during the time he spent at a madrassah in Indonesia.
oops, sorry, i clicked on the wrong comment and thought you were just making the same post again.
regardless, there's a big difference between your asserting he was a muslim for 25 years and your suspicion that he was a muslim when he went to a nominally muslim school in jakarta. otherwise, wouldn't you have equal suspicion that he was a christian when he went to a christian school there?