You can place blocks through glass panes

I've noticed, that if you do a corner with glass panes, you'll be able to set block through this corner

 

Link to video footage where I showed everything in detail: https://youtu.be/s4k1F1w2zxA

 

Step by step to do this bug:

1. create a corner with glass panes like on screenshot
2. stand up close this corner and place any block