I know that guy. I was on leave last summer and attended the silencer shoot at the KRRC. Ranb on SilencerTalk told me more about the story than was published in the Kitsap Sun. He said he was tired of waiting for the County Attorney to respond to his request for info on whether or not it would be legal to use a box to reduce noise so he installed it anyway and took some video of the test. He said it reduced noise at the sides but the first shot blew the box apart so he took it home to repair it. The next day the county wrote back saying it would be most likely illegal to use. He starting worrying and took his video down from the various forums he had posted it on then wrote to his Representative asking him to get an opinion from the State AG.
His Rep wanted an opinion from the ATF, so he wrote a letter and was totally surprised when he got a reply. He was all excited when the Washington State AG wrote an opinion saying that "a box is not a dangerous weapon" so the dangerous weapons statute does not apply to a simple box. I thought that a laugh and a half. He re-installed his shooting box and it got beat to hell after a few hundred rounds. He is trying to put something together made from steel drums now.
He is an ok guy, a so-so shot and generous with his ammo. He had about a dozen guns at the silencer shoot and let anyone who was interested try them out. He makes his own silencers but had lots to learn. He had a set screw blow out of a bleed hole in the back of one of his high powered rifle silencers which blasted him in the face with debris.
You'd think someone who makes their own silencers would know better, but as we say in the Navy, "the stupid shall be punished". He is rather hot tempered and has a warped sense of humor, but who cares when they get so involved with making guns more available to the rest of us.