NO Christian would say "My Muslim faith" accidentally. Not one. Not EVER.
I am not so sure about that kind of mix-up. Look at the woman in the Northwest who thought she was Black. Look at Jeb who thought he was Hispanic. Then, there is Jenner.
Some people do get confused. In 2004, John Kerry tried to enhance his resume by claiming several things that were actually done by Sen. Bob KerrEy.
Some people are easily confused.