I was designing a redstone device, and when I connected 2 wires together, rather than connecting to each other, they faced the opposite way. For example, If the wires were facing North and South, the wire would appear to be facing West to East and vice-versa.. Even though the redstone still works normally, it causes for lots of confusion. To reproduce this bug one must simply put 2 redstone wires adjacent to each other in no fancy way what-so-ever.
Yet another duplicate of MC-53384