To try an be brief, we hired ten bikes from a BMW dealer in Durban South Africa and did two weeks mainly off-road through South Africa and Lesotho.
The terrain varied from dusty rocky tracks to muddy tracks, steep rocky climbs and descents.
My friend Dave Green  was riding a brand new 2016 R1200gs LC and I will admit we had hit a few rocks hard, but no harder than I would have done if I had been riding our KTM's . Some of the terrain was so rocky that you had to maintain some speed just to get through them, I'm talking about 10-15 mph  not 60-70mph.
Anyway on a flat bit of dirt road Dave hit a small rock about 2 inches high and the front fork dislocated and he was thrown down the road. He had not dropped or damaged the bike in anyway prior to this fork failure.

Dave was injured, he damaged his shoulder, his hand and his neck and shattered his confidence. His helmet, riding gear and luggage was ruined.
We later looked at other bikes forks and found that probably 7 out of ten were developing the same fault. I was riding a 2016 GSA  LC and a gap was appearing on those forks as well. One was so bad it had to be collected by the dealer, I was told by the dealer to ride mine but ride it carefully?
When we returned to Durban the BMW dealer showed us another customers front forks that had developed the same fault.
We believe dealers changed all of our bikes forks and the other customers forks with like for like replacements.
Dave and myself wrote several emails of complaint to BMW and after months of no response and numerous phone calls Dave got an email aback from BMW saying that It was his responsibility under the hire agreement to look after the bike and there was no recourse to BMW. He also lost his £700 deposit on the bike
What really annoys me is that we have both ridden a lot of off-road on KTM's and Yamaha and never had this problem.  BMW promotional videos show the bikes jumping and riding through rough terrain, promoting the Enduro aspect of the bikes and when they fall apart they blame the rider.

The photos of the fork disconnected is of Dave's crashed bike, the others are of other bikes developing the same fault.