Chester Glitch

So I'm not sure how many people have run into this glitch.  I am in human form, and offline.  I was fighting Chester in Black Phantom form, and I backstabbed him killing him.  He said his death speech...Then stood up.  I can't lock onto him, but he's been standing there for roughly 10 minutes and as I type this he is still standing beside me.  He is invincible and gave me no souls, I can quit out but I have no tried that.  Instead I've been using this as an opportunity to get pictures of Chester in his BP form.  

https://2img.net/h/i1213.photobucket.com/albums/cc475/TolvoArt/DarkSoulsCharacters/Chester5_zpsdc4c6433.jpg

https://2img.net/h/i1213.photobucket.com/albums/cc475/TolvoArt/DarkSoulsCharacters/Chester4_zps03224063.jpg

https://2img.net/h/i1213.photobucket.com/albums/cc475/TolvoArt/DarkSoulsCharacters/Chester3_zps370e99e8.jpg

https://2img.net/h/i1213.photobucket.com/albums/cc475/TolvoArt/DarkSoulsCharacters/Chester2_zpsd14daeeb.jpg

https://2img.net/h/i1213.photobucket.com/albums/cc475/TolvoArt/DarkSoulsCharacters/Chester1_zps4d08c247.jpg

So, has anyone else run into this glitch?  Is it common, does anyone know what exactly causes it?  I'm was using a Great Club to backstab him, and the first hit of the BS didn't kill him but the second hit did.  Though here he is still standing, not responding to anything.  My fog gate is gone and I can walk to chester.

I am now talking to chester, his BP is still in the Township.  He has no dialogue change.

And now suddenly the BP died, and now his dialogue has changed to having killed him in BP form.

What a strange and mysterious game.

It sounds similar to the glitch that occurs online when you have summons and enemies stand up and don't give souls after dying. Never done it while playing on my own though

Yeah I run into that commonly, but usually the enemy dies after ten seconds or up to a minute.  This lasted for roughly fifteen minutes though, and I was able to enter another entire zone with the NPC staying alive.  Sort of amusing considering I had BP Chester in my world while I was talking to Chester.

Sounds very creepy, Maybe he's starting to gain sentience. MUAHAHAHA