Not at age 5 he wouldn't. If you'll read the law he couldn't voluntarily give up his citizenship until he was 18. And parents could not do it for him.
He could have done so, there is no record he did or did not.
Even if he could have done that while a child under 10, which he could not, there would have been a record of it. Again if you would read the law you would see that any such expatriation has to be done in writing.
He might well have his citizenship back, but NOT as a Natural Born citizen.
He never gave it up in the first place.
It is his IMMIGRATION status that is relevant.
Utter nonsense.
Where is the Indonesian law proving that?