Why did he apply for a J-1 visa? I've been on a J-1 a couple of times for research stints in the US, but my understanding is that for conferences, you can also make use of the B-1 visa [1], as stated on the State department's website. The B-1 is generally processed much more quickly, with the J-1 requiring a lot more documentation.

[1] http://www.travel.state.gov/visa/temp/types/types_2665.html#...