I think in practice, the first time someone needed to do this, a bunch of high grade academic cryptographers would acts as expert witnesses pro-bono. From there

I think in practice, the first time someone needed to do this, a bunch of high grade academic cryptographers would acts as expert witnesses pro-bono. From there, it would be like a hacking case - an expert explains the issue to the jury, who take a decision. Assuming it is technically sound, bitchain certification would win. Subsequent cases would be able to use the precedent, and win with less interesting experts.