I was just accepting the difference in our opinions but it appears you wish to continue , I'd counter that:
1. I suspect BMW was exaggerating for effect.
2. The size of a padded football player makes pinpointing specific areas of a body rather difficult. This argument about there being this part of the body between knees and head is all very well but it doesn't completely work. For example, how many times have you seen defenders flagged for a hit to the head when they clearly targeted the upper torso. But the size of the pads and the nature of the impact often results in the head being hit too. As for the lower torso and waist, those are probably the sturdier parts of a person's body and a hit there is no guarantee to bring someone down, particularly in these days where wrapping up to tackle is not the norm. So, you need to hit them in the legs, which as in the chest/head relationship mentioned previously will inevitably hit the knees too.
3. I suspect BMW was exaggerating for effect.
4. To be frank, I couldn't care less about what he said, the guys a moron, but to think he was stating his intention to target other player's acl's just struck me as being too simplistic.