I noticed when you click more options it is grayed out so the user does not click again. However, right before the next page begins to load the button resets and the user can hammer it again. One time I managed to cause a server error, no details given on the webpage.
Unfortunately, there's nothing we can really do about it, except for limiting the browsers a bit. It's cause by a Firefox bug/issue, where using the back button would leave the buttons disabled. It may be reasonable to only do the unload behavior on FF, assuming that is the only browser that needs it.