My mate received and then sent a Bitcoin transaction before his wallet was synchronised and it worked perfectly His Bitcoin wallet was only 1% synchronized with the network and yet he was able to receive and send bitcoins without any problems?!

What are the implications / ramifications of this?

What does this mean?
You don't have to do anything to receive Bitcoins. That's entirely passive. Your client doesn't have to be running.

To send Bitcoins, you just need enough information to form the transaction. If you have the transaction that sent them to you and you know it was confirmed, that's sufficient.