When you middle-click to copy a block to your inventory whilst in creative mode, if that block is a rotating cog, then when you replace the cog, it maintains its rotation without being attached to anything.

That’s because in creative you can pick blocks while keeping their nbt data. You can do the same with chests, signs etc.. If you have a chest with items inside you can use the pick block feature to get a copy of the chest with all items inside in your inventory.
This is a vanilla feature and I personally would not consider it a bug.

This issue has been addressed in 0.2.3. Thanks for the report and feel free to re-open if need be.