So I beat it but wanted to go back to explore more/etc.. I go back to the last save before going to Hoover Dam, which is right before the conversation with Yes Man that took me there.. When I go back to Hoover Dam, it's already on fire, there are Legion everywhere, with NCR killing them, and the quest is already on No Gods, No Master or whatever.. Even though it was a permanent save BEFORE ever going to Hoover Dam (pre-Presidential visit, meeting the Major, adding the chip, etc.) it is acting like all that is already done.. Pretty fucked up..
I can go back like 2 hours and it's not affected..
These games would be GOAT if they didn't have so many fucking bugs..