I think we BOTH know that he wasn't asking if you have any "specific knowledge" about who to blame. He was CLEARLY asking if you had any specific knowledge about ACL tears and how they happen and what the factors are.
Seriously? Really?
A broken collar bone is one thing, as it doesn't happen too often and a broken bone simply cannot be attributed to too much or too little conditioning. Bad luck and a 300lb defensive lineman made that happen.
As far has tearing ACLs I DO believe, in someway, that conditioning has SOMETHING to do with it. It is either too little conditioning to too much. I read that Barclay "took a bad fall in practice" and tore his ACL. How often have you fell and tore a ligament? My guess is never to very, very rarely.
Lets use myself as an example here. I am an overweight guy, not "fat guy in a floaty chair from WALL-E" overweight, but overweight none the less. I know that due to my weight there is more stress put on my heart and joints. Therefore, I am more likely to suffer a heart attack and have bad knees and ankles in the future, if not arthritis.
Now then, as an athlete these guys build up their muscles and sometimes to the extreme with very little body fat. These muscles are now extremely taught, and as such so are the tendons and ligaments. It wouldn't take much to make one tear or rip, or at least not as much as it would take for one of US to tear our ACL. A guy like Barclay probably works out his legs to most as he needs to plant himself in place and/or push and keep the defense away from Lacy and Rodgers. So, his awkward fall in conjunction with his "over-conditioned" legs = ACL tear.
Just my $.02