collapse.js breaks when the hash contains jQuery BBQ-like query string

If a collapsible fieldset is present on the page and the url contains a hash intended for jquery bbq, e.g. /#?foo=bar, then Drupal.behaviors.collapse.attach breaks because the hash is being used completely as a jquery element selector.
It seems to me that to use the hash as a selector is a big assumption.

I'm attaching an example diff that might address this, but I feel that it's only covering up a larger design issue of fieldset.collapsible.