Haha no worries about the ranting.
As for your friend, well, he was tricked by the enemy; it's simple as that. If he doesn't put his protections (he should meditate daily and put an aura of protection around him) then he's extremely vulnerable to enemy attacks.
It doesn't matter what he did... as long as he got his mind straight now.
But, if I were him (your friend), I wouldn't just continue (or re-start) meditating and simply go on like nothing ever happened. I would really want to show Satan that I have really set my mind and my faith straight, and I would try to reach as many people as possible; in general, I would fight for him in any way I can.
One way we can fight is to do the Reverse Torah Rituals (they are extremely important, as they reverse the jewish curses that exist in the bible). Another way to fight is to do "online warfare". He could (if he has the time of course; but even 10 minutes a day is more than enough to reach people) search for youtube videos that have a christian or a Satanic theme (with the false christian beliefs about Satan) and he could write the joyofSatan link in the comments... Or he could search on yahoo answers or other websites where people ask questions on religious topics, and he can also explain in a few words how reality really is and give the joyofSatan or exposingchristianity websites.
From my experience, I have found that the more you study (the websites and the Sermons written by our High Priests) the more easy it is to converse with someone with opposite beliefs, and to persuade them to doubt their own beliefs. We do not terrorize people or brainwash them to make them believe what we believe. But we need to make them wonder and doubt what they have been taught for so long (jewish brainwashing).
So yeah, if I were in your friend's shoes, I would fight for Satan with all my heart, and of course daily meditate and study, in order to better myself, and the world around me. I would do my best to bring people closer to Satan (WITHOUT endangering myself, of course... you can make someone doubt christianity, without ever mentioning Satan).
So really, don't worry, and tell your friend not to worry either. Tell him to start-restart with the meditations and keep on fighting.