The latest event that just happened on bitcointalk.org that saw the site compromised and down for quite a number of days would've scared off new people interested in Bitcoin. This would lead them to think that the whole Bitcoin network is open to hacks, even though this is wrong. This would also catch media attention, causing people to go and talk about how 'Bitcoin is bad' because is has been 'hacked'. This is not how we want it at all, as it is all wrong. I hope the future of the forum, and Bitcoin in general, would not encounter such problems anymore.
Anyways, with that out of the way, a question: Should you tell the person you're introducing Bitcoin to about the forum? If yes, then they might find out about the hack. But then the forum is a place for support for them. So should you or should you not?
Tell then that the forum being hacked won't mean that their Bitcoins will also be hacked. Many websites get hacked and Bitcointalk is no exception.