Firstly, it is the drivers responsibility to make sure he is insured, not the owner. your Dad will not get into trouble, at all.
Secondly, if your Dads friend got flashed by a camera, it wont matter that he's not insured (as long as he doesnt tell them). Just get him to sign the speeding ticket, admitting that he was driving. They will ask him to send his licence ONLY, where he will receive 3 points and a �60 fine.
If he doesnt admit to being the driver, your Dad will get into trouble.
The only way your friend will get into trouble for no insurance is if he got pulled over by the police, and given a producer.
in which case, he'll most likely get a small ban PLUS the 3 points.
It really is just a question of damage limitation now.
Get him to confess to speeding in your dads car.
Or your dad will get the speeding points.