I had an interesting discussion on this board about a year ago (?) with a woman who had been a convert to Islam for a few years (as a result of marriage to a Muslim) and who was also an exMo. I wasn't clear, though, on whether she had been Mo prior to being a Muslim, or if she'd converted for a while to Islam first and later on to Mormonism. I'm always struck by some of the parallels between the two religions. However, given that the clear penalty in Islam for apostasy is death (at least for males--female apostates are sometimes shown more leniency), I'd be very surprised if there are many, if any, *open* converts from Islam to Mormonism.
That's great he hasn't been threatened. A former student of mine from Afghanistan was was looking into joining a Christian (non-denominationsl) church here in the Bay Area about five years ago. He started receving death threats even from immediate family members here. I don't know what he decided to do ultimately, as we didn't remain in touch after class ended.
There was also an item on the local news here a few years ago about a church opening that was for Iranian Christians, many of whom were converts from Islam. According to the report, there was a strong security presence at tbe church due to worries about apostates' safety. I don't know, however, if there was security only at the opening of the church or if they've felt they needed to keep being that cautious.