When args is present you have errors that are related to an input field. An example of args is that 'add domain' form, where you get something like:

{:name => ['Domain name can't be blank', 'Domain name something else...']}

So basically I'm making sure that only errors that are not inline in forms (e.g. :base) will have collapsible details with "Show more...".

Also I don't think :not could be an array. That's a check that was already present in this method.