Beans and other legumes are among the most nutritionally valuable vegetable foods. But they also contain a protein that can be toxic in sufficiently high concentrations if the beans are eaten raw.
Starch is not protein. Starch is what's left after you remove the protein, cellulose, etc. As the source you quoted indicates, the toxins are proteins, not starches.
Raw mung bean
starch appears to be not only safe for me, but beneficial in the doses I consume it. Whether it is safe, beneficial, or harmful for you is something that only you could determine, and there is always the unknown of long term effects with any food, so we are all rolling the dice to some degree. The scientific dig evidence, thousands of years of experience of HG's and other traditional peoples, scientific studies, knowledge from biology, chemistry and medicine, and other evidence can provide clues about what might work in the longer run.
I actually found that by just soaking mung beans, I could make them reasonably edible, though not yummy, and it took a lot of soaking, and I also changed the water at least once. They didn't taste terrible to me, though to each their own. I'll probably experiment some more with that at some point. I forget if I've tried something acidic with the beans yet, such as lemon juice or vinegar, which might also help them ferment. I might try making the sprouts some time too.
My friends and relatives tend to think that many of the paleo foods discussed in this forum taste terrible or are too disgusting to even try and that modern highly-processed junk foods taste much better. That doesn't guarantee that the latter are healthy or the former unhealthy.
Our ancient ancestors ate legumes for millions of years before the advent of cooking. Many of the foods they ate millions and even thousands of years ago are not available to us today, so we make do with what is available. We can't eat the exact "perfect" diets of the past, if they were ever perfect. I used to avoid all legumes and found I did better by including some--probably still less than in the avg American diet. I do what works for me, which may not work for others. Each person will have to figure out what works for them.
Interestingly, legumes were the only food type common among all the Blue Zone healthy nations (
http://en.wikipedia.org/wiki/Blue_Zone#Characteristics). It at least appears that eating a certain amount of the legumes consumed by these societies is not associated with severely negative health.
Some legume foods available to me are edible raw, fitting NeaderThin author Ray Audette's definition of "Paleo" as being any food edible to anyone who has just a sharp stick--such as jicama legume tubers, tamarind legume pod fruits, carob legume pod fruits, and Bambara legume groundnuts. Of those, I eat jicama and tamarind. Interestingly, my ability to tolerate tamarind and other legumes seems to have improved since increasing resistant starch and other prebiotics in my det. Some legume tubers commonly eaten by hunter gatherers, such as Ekwa hasa (Vigna frutescens) and Shumuwako (Vatoraea pseudolablab) are also edible raw (Sex Differences in Food Preferences of Hadza Hunter-Gatherers,
http://www.epjournal.net/wp-content/uploads/EP07601616.pdf). Some Instinctos, such as Iguana (Francois), eat cassia fistula legume pod fruits.
Toxins and anti-nutrients are frequently focused on in Paleo circles. Until recently, it was rare to see Paleoists discuss the anti-toxins and pro-nutrients in foods, such as resistant starch, butyrate, and so on. That has been changing. More and more people are examining both sides of the toxin/anti-toxin coin, instead of just focusing on one side, and examining resilience-promotion, not just toxin-avoidance.
(Note to readers: This is a journal, not a debate thread, and this info is meant to be an explanation in response to a question, not a debating point, so if anyone wants to debate any of this, please put it in a debate thread or start a new one. Thanks.)