The extent of this bug is not well known, however breaking and placing blocks near lights (and not messing with the lights themselves) appears to cause some issue.

I can repeat this issue by placing two lights near each other (one in the ground to be covered)
Covering the block in the ground with a block on top causes the engine to derp, leaving the red light above when it shouldn't. Breaking the block, and placing it again causes the lights to vanish as expected o.O

This behavior does not occur if the blue light is missing. So something about colored light on BOTH sides of a barrier appear to cause the lighting engine some trouble.

This occurred when mining in low light conditions