Firstly it is against paypal rules to sell goods and accept friends / family payments. If paypal finds out that you are doing this regularly then you risk your paypal account being limited.
Secondly by accepting money that way you were trying to negate any buyer protection that your buyer had, another reason its against paypal rules.
Thirdly by accepting money that way you also lost any seller protection that you had.
Whilst a buyer would have no paypal buyer protection for sending using the friends / family option for ''non receipt of item'' OR ''item received but not as described'', they would still have protection for an unauthorised payment OR a chargeback.
Normally if a buyer wins an unauthorised dispute OR a chargeback you would be reimbursed under seller protection but by trying to negate your buyers protection you lost your own seller protection at the same time.
What you could have done is accept payment by the goods / services option and then you would have had seller protection.
You would have known.
If he used the family / friends option then you would not have been charged a fee AND the address of the buyer would not have shown up on your email paypal receipt.
So if it was a goods / services payment you would have had the address to send the item to but with friends / family payments you would not receive the address.