Light from fire won't go away after extinguishing automatically

So pretty much, I was doing a no jump challenge, (Which explains all the stairs) and obviously this isn't game breaking, but I encountered a zombie in the place the screenshots show, and with only a Flint and Steel on me, attempted to set the zombie on fire, which would obviously create some light. After traveling away for a while and coming back, I noticed that there was some random patches of light in the places I lit up. As you can see in the screenshots, the fire is long gone, so what is causing the light? Is it a weird bug with the lighting engine at sunrise, or the light from the fire lingering after being put out? I don't know, but one more thing...

 

 

 

 

 

 

 

 

 

 

 

Please don't judge the fact that I have UK English on it's just a funny joke.