The above video is of Mani deadlifting 65kg for 5 reps at 54kg body weight. This is a very good effort considering it is only his 7th time deadlifting. He still has plenty of improvement to go with his deadlifting technique but it is coming along really well.
I find many young athletes get injured when performing the deadlift but a lot of the time it is because they have not been shown the correct technique and many trainers program it way too early and expect their athletes to lift way too much. Also the young athletes just aren't monitored closely enough to ensure they are lifting with the correct technique.
Many trainers of young teams program all the big lifts like the deadlift, squat, and bench for example thinking they are writing the best program possible for their athletes but don't realise that they need a lot more general preparatory work before introducing these lifts. This is why you see the injuries in the gym. It isn't because the lifts are dangerous it is because of they way they are performed. You can't just verbally coach a young athlete through a deadlift. Sure a cue here and there helps but you need to make them strong enough and mobile enough to be able to get into the correct position physically. If they can't do this then you need to build them up with more accessory work first.
Being patient and constantly monitoring young athletes is critical for their safety, performance, and long term progress.