http://software.hixie.ch/utilities/js/live-dom-viewer/?saved=3556 According to https://www.w3.org/Bugs/Public/show_bug.cgi?id=27430 the call to click() in the testcase should only operate on the target element, which in the testcase is not activatable (an anchor lacking an href attribute). The authentic activation steps explicitly say to find the nearest activatable element, but synthetic activation (ie. HTMLElement.click()) should not.