To be fair it’s not like you have to actually straight up injest them to try. I’m sure there were protocols.
Like first you touch and wait a couple hours. If nothing happens try rubbing on your skin and waiting a couple hours. If nothing happens rub it in your mouth and wait a couple hours. If nothing happens chew a tiny bit and spit it out and wait a couple hours etc.
It’s not foolproof obviously. But its a lot safer than seeing a new shroom and full on eating it.