I'd think this is really good advice, Chris. Staying in higher rep ranges where form can be really nice, and staying away from heavy singles and triples would probably go a long way toward reducing injury risk.
Also, I was thinking there's generally less risk of injury when lifting at home with your dad, than when young men are horsing around during football practice trying to best each other.
About the young team of kids I saw competing, they weren't doing any really ugly lifts. I saw some knee cave on squats in one of the girls, but mostly they weren't lifting weights so heavy that they sacrificed form.
It would be interesting to know the incidence of back injuries in sedentary people, as compared to athletes or weight lifters specifically. It seems like a lot of people with bad backs are overweight people who mostly move from the couch to the fridge.