lol yeah I agree! A beginner rider is going to be very careful and a little nervous and won't try anything stupid. More advanced riders may be jumping and generally going faster and taking more risks.
I notice that with myself and my sister. I think 'wow! What a great hill to gallop up!' and so I do. My sister is a little nervous so she just canters up. I think i'd be more likely to fall off because of the increased speed and increased likelihood of my horse tripping or shying and making me fall. The increased speed means I'd hit the ground with more force and hence have greater injuries. My sister is less experience so may be more likely to fall, but she's going slower so injuries will be less. This applies only as a general rule, there are always exceptions.
I don't know why My2geldings is so sure the information is incorrect - most doctors read medical journals to gain up to date information on their work. Oh well, I think they're accurate anyway and so long as my university and the government authorities here agree, I should be ok.
When I bestride him, I soar, I am a hawk: he trots the air; the earth sings when he touches it; the basest horn of his hoof is more musical than the pipe of Hermes. ~William Shakespeare