To be fair to HK we should also note that the owner/user of that gun used a suppressor not approved by HK for use with their guns. While at first glance, it may seem petty to mention and even require approved devices only, the r&d that goes into HK products and approved accessories is substantial.
When developing the USP T tactical and approved suppressor combo, it came to light that suppressors with the wrong Nielsen device spring ratings would damage the gun and cause stoppages. HK and KAC ran extensive r&d at considerable cost to be able to guarantee the combo for life. That suppressor is twice the cost of the alternatives so many users will ignore the printed warnings in the USP manual and mount some other option.
In this case, the user ran it enough to cause damage and it appears he wanted HK to be responsible for his decision. When the USP Tactical was developed, his suppressor choice wasn't even on the market. In which way is it fair to expect responsibility from HK for devices made decades after the fact? Was there an equal expectation of the suppressor manufacturer?
To be clear, I like HKs. I am an enthusiast enough to know the full story. One could say I am a fan......of HK and the full truth.