Just got it right now, luckily I had someone with me who could start the extraction (to Necralisk) timer and saved me, so I got to keep my catch & affinity.
Well, now that I've found this thread exists and added a "me too"... I'm off to the Support section to submit my log files!
EDIT: Figured I should add some extra information.
So when this happened, I was able to aim my spear but NOT throw it... My escape menu worked (as did the Abilities & Melee Combos sub-menus). Chat worked (but /unstuck didn't change my location, just rotated me and changed my animation/stance).