I finally got the leaking hot end (and subsequent throat issues) cleared up and printed some really nice pieces yesterday, easily as good as I’ve ever seen on my printer. I started a big print (11 hours or so) just before I went to be, watched it through the first two layers and then went to bed. When I woke up this morning I was presented with this. Has anyone seen anything like it before? There’s no indication of damage to the extruder holder part so I have no idea what could have knocked it off the mount. It’s PLA but I see no indication it’s been too hot, no deformities at all… 
Whoa, nothing that big, maybe a marble size, yikes. Warm it up and carefully and slowly try and get it off without ripping any wires.
I’ve got the heat on and will be really, really careful about the wires into the hot end. I’ve got both a heat gun and a torch, so it should be doable. What I’m most concerned about though is how it could have happened in the first place. I just am coming up blank in trying to visualize a scenario where it gets knocked off. I’m thinking it would have to be something where extruded filament hardens before a head movement that then forces it off, but that seems awfully unlikely.
something that big I would assume came out of the throat side of the heat block, loose nozzle, really loose. So instead of squeezing out of the nozzle .4mm hole it went out the bigger hole that took less pressure. Won’t know until you get some of that off though.
Nope, it all came out the nozzle, just curled and curled until there wasn’t anywhere to go. It came apart pretty well once I got things hot again. Apparently it had pulled the parts off the blue tape, then just kind of wrapped itself around itself for the next 10 hours while I slept the sleep of the innocent. I also realized that I hadn’t spritzed the bed with alcohol before that failed print and it might have had something to do with it not sticking. I had watched through the first three layers and it was looking beautiful when I went to bed. 
I made a mod to my extruder, a little printed spacer to better line the pulley up to the feed hole (the stock one was off by about 1mm) and things are working much better today.
I had one do that to me as well. Part came loose from the bed and just slid around the plate with the hot end. It was bad enough that I had to replace the hot end.
Mine had a lot more plastic, but nothing got up into the extruder mechanism, so I just had to melt it off the hot end. I did swap the nozzle out with one I had soaking in acetone (after torching the remnants of plastic left behind) and scraped excess off the block, but it’s all good now.