here are two very effective and simple methods to clear security HOWEVER, be warned the first will result in some serious paperwork if caught:

Method 1

1. merely do OLCI and copy and paste the entire page to a blank Word file.
2. in the word file change the flight details to match those with a flight departing within 3 hours of the son's arrival.
3. change the pax name to the friends
4. delete the FF# (or better insert the friends valid number)
5. print the Word file (for best results print in B/W)

and, voila! your friend has his own BP to clear security with no charging / canceling tickets.

Remember to save the original OLCI webpage for future use.

Method 2: go to the main check-in counter and politely explain the situation and ask the checkin attendant for a non-passenger pass through security.

I prefer method two - but method one is very effective (for the non-nervous types).