Here's the situation:
- I finished Cass's quest (Heartache by the Numbers) peacefully, with stealth. I was not caught by the Crimson Caravan nor the Van Graffs with my sneaking around for their secrets, and Cass and I reported them both to NCR.
- I am idolized by both NCR and (I'm not sure how this happened) Crimson Caravan.
I popped into Freeside to go looking for Rex, because I thought I needed him for Jimmy's Well (oops, didn't), and the Silver Rush Crier started shooting at me. I took him down, and as I approached the Atomic Wrangler, a bunch of Van Graff thugs appeared outside the Silver Rush. I dispatched them, went inside, and Gloria, Jean-Baptiste and their thugs were all trying to kill me. Well, being an NCR guy (erm, this run) through and through, I wiped them all out.
But my question is why. They didn't catch me when I was stealthy (I was using a stealth boy and showed [HIDDEN] the entire time), they didn't catch me stealing (why not, I was using a stealth boy already), and I got away clean with Cass. So why were they hostile the next time I entered Freeside?
Best Answer
The Van Graffs and their thugs are set to become hostile as soon as you complete the quest in a negative way for them.
If you need an in-game explanation, they might have an informer in the NCR army.