We cannot effectively apply local social mores to that behavior.
It would be perfectly reasonable behavior to a true muslim to hide his faith so as to be in a position to cause maximum damage to a people not willing to fully submit to Islam.
A true muslim as defined by the koran hadiths and sunnah....Everyone else is a hypocrite and will feed the fire eventually.
It is a time honored tradition with a long and storied history called
taqiyyah.
'Taqiyya': how Islamic extremists deceive the West
"What is taqiyya, as referred to in the indictment? The Islamic tradition of taqiyya stretches back to the sixth-century A.D. when, following disputes over succession after the Prophet Mohammed's death, the minority Shiites developed taqiyya, or "holy deception", to conceal their "true" beliefs from the Sunni majority and to maintain operational security for their jihad/ terrorist missions in the Dar el Haab--The Domain of War"