Bug that I saw on a stream

I was watching a stream the other day and there was a clear bug shown on the stream. This bug is not only annoying but can cause problems in the future if this happens more http://gyazo.com/d618db6d675b58f6b5d8bc4805af32cd http://gyazo.com/093f27f24a73abb7d9ba93d674a75886