Here are the facts so far:
Kneebinding has only 400,000 days of use maximum, the real number is likley much much lower.
Kneebinding is known to have caused or contributed to at least 10 ACL injures, with an additional 5 suspected ACL injuries attributed to them
Kneebinding has not been proven to reduce incidences of ACL injuries, at best it is no worse then the other brands.
800 ski instructors/patrollers, 100 days a year, five years would be 400,000 days for just 10% of Knee Bindings
Add in the other 7200 users, 20 days a year, five years that would be 720,000 days of use.
Likely more as we are now in year six and the 8000 number has gone up and another year and another 224,000 days of use.
As for Knee Bindings causing or contributing to ACL injuries while skiing, that's a bit upside down as all Knee Bindings would do would not prevent the ACL injuries.
But "known" ACL injuries with Knee Bindings are not known other than the one posted here in detail which seems clear it was not an ACL tear that Knee Bindings would have prevented. Given the nature of Knee Binding customers, one would think they would be very vocal about Knee Binding not working when it was supposed to in regard to the backward skiing fall that accounts for 70% of ACL injuries.
It would be interesting to see actual data but then no binding mfg provides the injury data on their bindings. Knee Bindings has certainly done way more than most on being transparent.