I took that into consideration , the bike had to be moved for emergency crews access 30 yards further up the hill .Well done you, hoping for a good outcome for the biker due to you taking charge of the scene, sounds like you did everything you could for the best outcome. It bugs me these days that bystanders are more interested in videoing an incident/accident with their phones for social media instead of helping.
One thing to consider about your account was the bike and debris should be left as the police may need it for evidence if it turns into a fatal accident.
There was so much sharp stuff over a 30 yard circle tyres would be punctured and dangerous to knee down in . Plus it gave shocked people including the lady driver something to do as severe system shocks can be nearly as dangerous as the incident itself .