I am not sure it was as erroneous as people say. In Mexico they grow "tomatillos" which are similar to tomatoes except they are smaller and stay green. They need to be cooked to be safe.
It could be generation of breeding them selectively in Europe that made them safe to eat raw.
Tomatillos aren't very closely related to tomatoes at all (they're a gooseberry) and are safe to eat raw -- you just shouldn't eat them raw when underripe.
That's what I heard, yet looking at WP it classifies tomatoes and tomatillos in the same family whereas gooseberries are a different order. I am not versed-enough in botanics to know how relevant this is, but I wonder what is true or not in these.
Ah, apparently its close relative is not the eurasian gooseberry but the cape gooseberry, which is the same genus as the tomatillo. They're also nightshades like peppers and tomatoes, but so is tobacco.
It could be generation of breeding them selectively in Europe that made them safe to eat raw.