Maybe it's karma. Maybe it's Maybelline, maybe its Mjollnir, but whatever it is, this is an interesting bug, issue, whatever it is.
I am in the start of Broken Steel, and after having gotten a message that further ingestion of the FEV-laced water would cause my death, I proceeded onward and had no clue what it was. I went onward through the bit where you assault the communication array and had no issues there, but when I head back to the citadel, I got another message, ignored it, and then after talking to Lyons, I die. Just...ded. Load up again, and it happens about the same time.
Now my first thought, in addition to what the hell, was that this may have been connected to whatever randomly keeps giving me the camel of the mojave perk and the not a drop to drink challenge, but puppetron here in the chat pointed out that whenever NPCs Idle drink things, that flags to you. So, if it is legit, then it is a pretty good explanation on what is going on with it. On Risewild's suggestion, I'm uploading a save that was done right at the start of the jefferson memorial, which gives you ample time to check out how the thing works. I'm running a skill uncapper, and some of my skills are beyond 100, but my level is not.