Big Bug with Column Access Rules

They are working in a VERY inconsistent manner.

Here are the rules.

here is the column that only OWNERS should be able to change.

Except I am logged as a non owner user and I modified a formula, creating an error.

Now, the most ironic and weird thing? I can´t UNDO it, because when I try to undo, THEN it gives me the message the user can´t updated that field, according to access rules

ok, the “Allow Editors to change formulas” rule was clicked on, because I was doing some tests the other day. I hadn´t noticed it and it was probably the cause for the weird behavior.

Still, why would I be able to change the formula to an error state and then be prevented from returning the formula to it’s previous state?