The miner seems to call Block#getMetaFromState directly instead of invoking Block#createStackedBlock when creating ItemStacks for silk touched blocks.
The vanilla silk touch logic will also invoke Block#createStackedBlock, as can be seen in Block#harvestBlock.
The problem is that this can set a non-zero metavalue to the ItemStack, even if this is not intended by the block.

This causes issues like CyclopsMC/EvilCraft#515, and possibly also for other blocks like vanilla Redstone when it is activated.

Fixed, thanks