He's a fine musician. As such, he may be safely ignored otherwise.
For what it's worth, Brian May is a published astronomer and was ABD in Astronomy. That being said, I still disagree with his conclusions.
I think the article is a bit alarmist. We're talking 1 in 5500 odds that it will hit the Earth somewhere. It's not like 1 in 1000 odds that it will hit NYC, and 1 in 5 anywhere else on Earth.