This poll is bound to be not very precise.
My decision would largely depend on a whether he is leaning towards militant islamic fundamentalism.
If he doesn't then I would apply the same standards to him as to any other person (how long do I know him, do we share similar views and ethical bounds etc).
That said, any kind of fundamentalist is a very unpleasant company to me, be he muslim, christian, hindu or whatever.
Regards,
Trooper