[mrob]

Not true. Incorrectly cooked kidney beans (and to a lesser degree other beans) can cause severe vomiting and diarrhea, because of phytohaemagglutinin toxicity, which needs prolonged heating to destroy:

https://en.wikipedia.org/wiki/Phaseolus_vulgaris#Toxicity

[nommm-nommm]

Improperly washing vegetables can lead to a really bad time as well.