I experienced this myself, and noticed in many videos on youtube “funny moments and fails in kingdom come: deliverance”
The scope of the bug is – player is jumping high (altitude varies from case to case), personally I experienced this when I have had a Swordfight Challenge against Hans Capone, this bastard won me without even damaging me! So in the beginning of a fight a blocked his light attack (the one when you “sting” your opponent), and all of a sudden, Henry jumped like 4-5 meters high, and fight was ended in a favor for Hans.
When it comes to a videos on youtube, seem like I’m not alone with this issue, also please notice that some experienced an issue when your character is continuously ascending high in the sky outside of a combat.
That leads to the point that if you jump that high, you could die and as a result – loose your progress.
P.S. Is it a privilege for backers or purely for devs to post bugs here: http://support.kingdomcomerpg.com?