Well, this IS sad. Your friend told you lot's of wrong things.
First you must know that CURSILLO is NOT a retreat at all. It is more an educational matter, "a short course in Christianity". I think your friend was a little 'pushed-in' to attend, he was not ready to go. He maybe wanted to go to a retreat.
It's a very big responsibility for the sponsor: to pray for it a long time to get the canditate ready and for his understanding of Christian values in the world.
CURSILLO is about 'Apostolic Action', what can I do in service to Christ? How can I help to spread the word of our Lord? Which is my talent? what part of "the Body" am I?
This is CURSILLO, for strong leaders who want to share their life with Christ....
So please look into it for yourself, you have read the Posts before yours I guess, and I hope there will be more answers coming up now, because the CURSILLO Family is strong and growing.
If you have any question please ask - the CF is there for you, and then make up your OWN mind, pray about it!
Your Brother in Christ,
Norbert