They let him brew potions without supervision from an expert? That sounds rather unwise. I hope they have the room well warded, so any explosions don't blow up the entire school.

Yes, I realize that first-year potions would be the easy ones that shouldn't cause explosions. But the boil-removing potion destroyed a cauldron because of a simple misstake. And if Ron simply dumps whatever ingredients he can find into a potion without looking carefully to make sure it's the right ones....