Gosses at ten weeks mate, yes, but a Harris, no way.
If he picks it up at 10 weeks then i would put money that it will be a screamer, i had one like i said, at 13weeks i think and it was a massive pain.
15 weeks minimum for me, but we are all different.
Plus, he will have problems tethering it down. If he gets it mid december and, lets say it takes him 4 weeks to fly it free( i dont know his history/skills ), it will need to be tethered when the heavy frosts of dec/jan hit. If the lad wants it he will get it and no-one will stop him but a 10 week harris in december has problems written all