I don't know if this helps, but this article seems to suggest that blue-throat triggers may be reef safe. The article is mainly about crosshatch triggerfish, but the last paragraph does mention blue-throat triggers and that...
"They should not pose a problem with corals in an aquarium and tend to have a more placid disposition than many of their triggerfish brethren"
http://www.advancedaquarist.com/issues/oct2002/Fish.htm