Let's take something else: vodka. Poisonous or edible? Clearly poisonous: if you drink a litre, you may feel nauseous, lose your balance, slur your words, throw up...
On the other hand, generally recognized as edible: many people consume it regularly, most doctors wouldn't tell you to never consume it, recipe books include recipes using it, etc.
Many (identified!) mushrooms are on a similar level of toxicity: one is fine, a kilo will make you nauseous, twenty kilos can kill you. Whether this is toxic or edible is to some extent a cultural construct. The dose makes the poison.
On the other hand, generally recognized as edible: many people consume it regularly, most doctors wouldn't tell you to never consume it, recipe books include recipes using it, etc.
Many (identified!) mushrooms are on a similar level of toxicity: one is fine, a kilo will make you nauseous, twenty kilos can kill you. Whether this is toxic or edible is to some extent a cultural construct. The dose makes the poison.