I assume you are saying that his religion required this action. Fair enough. If we allow all kinds of exceptions for religious practices, then how can we also object to Muslim women keeping their faces covered in driver’s license pictures?
Firstly, he was obviously scanned and wanded in the airport where he was wearing these things openly.
Secondly, this country was founded on freedom of religion and should be protected from hysterical ignorance (not on your part but the pilot/crew).