The enchantment command can be run in survival mode without operator permissions.
I ran the command:

/enchant @p minecraft:efficiency 5

whilst holding a wooden pickaxe

What I expected to happen was:
The pickaxe would not be enchanted and I would get an unknown command at position 0 error (How the game seems to handle invalid permissions)

What actually happened was...:
The pickaxe was enchanted and I got the message "Applied enchantment Effeciency V to Levertion's Item

Steps to Reproduce:
1) Obtain an item which can be enchanted.
2) Run the enchant command with an enchantment that item supports whilst it is in your hand.