He didn't "gameshare" his account he's not an idiot... He's has never had an issue with his Amex, and only uses it for certain things... Idk if it's a weird coincidence but it's awfully suspicious when u haven't used ur CC in months and them u go on PSN and 3 days later his info was stolen!
First it's impossible to make anything associated with personal information 100% unhackeable, that will never happen. With that said, I'm sure Sony is well within the rules and regulations for safe guarding people's information.
You make it seem as though the timing is important when in relatity the fact that he hasnt used the card in months is actually irrelevant. When hackers steal information they often sit on it for a while in the hopes that a theft will not be associated with a particular hacking attempt and that people will forget to change their information. In addition personal information is often sold to people who are then the ones that use it which also takes time. So the fact that it happened 3 days after he went on PSN actually suggests that going on PSN was NOT what caused his info to be stolen.