“AFAIK, ricin doesn’t work that fast.”
“less than 10 hours” according to the CDC.
How fast was this?
It said the couple was found dead in their room, not sure how long it took to all go down from when they drank the bottle to when they were discovered, or how long before they had passed before they were found. I read it can take up to 3 days for ricin poisoning. Plus, the symptoms come on before hand - so they might have reported something was wrong when the sweating, fevers, cramps started to get severe. So if we take 10 hours maybe on the short end of the spectrum, 3 days on the long end - for 2 people to die in roughly the same time period, I would guess something known to be faster acting. Obviously I am no expert on this stuff just what I’ve seen and read online.