Question

The best advice I can give is don't leave your printer unattended.  Now I realize that isn't always practical but at least get to the point where you are comfortable with your printer.
No one is going to say for certain what went wrong but I would guess you need to do some calibration.  Focus on your extrusion steps per mm and extrusion multiplier.  If it is over extruding the nozzle will catch the print and cause shifting.  You will also want to master adhesion before you can comfortably walk away from a printer.  Do this by ensuring your bed is level and the first layer is getting squished till it looks like a flat ribbon going down.  If you spray the glass with Aqua net extreme hold your prints will stick better.  If a part of your print begins to lift that can also cause the print to hit your nozzle, resulting in shifting.

Last time this happened to me, the filament had gotten tangled on the spool.

Haha I should start a 3d-printing troubleshooting betting service!
I'll put my money on the crash+curl, it got me recently too.

Also, welcome to the forum, dax. You won't be able to post links etc. until you have 5 or 10 posts, but if you upload the image to imgur (or similar) and share a text link we can probably have a look, maybe offer more specific advice based on the print.

Happy printing.