Re: [Events] removeEventListener on EventListeners currently being processed

The change appeared to occur between then 7 March 2000 and 20 May 2000 drafts.  The language is pretty explicit, the current Xerces-J (and gnu whatever) implementation is consistent with the 7 March draft and inconsistent with the 20 May and eventual recommendation.  

This does not appear to be an editorial or clarification issue, but invalidating a purposeful change to the spec.

From http://www.w3.org/TR/2000/CR-DOM-Level-2-20000307/events.html#Events-EventTarget-removeEventListener (2 March 2000)

This method allows the removal of event listeners from the event target. If an EventListener is removed from an EventTarget while it is processing an event, it will still be triggered by the current actions but will not be triggered again during any later stages of event flow, such as bubbling.
Calling removeEventListener with arguments which do not identify any currently registered EventListener on the EventTarget has no effect.

From http://www.w3.org/TR/2000/CR-DOM-Level-2-20000510/events.html#Events-EventTarget-removeEventListener (20 May 2000 and very close if not identical to the text in the recommendation)

This method allows the removal of event listeners from the event target. If an EventListener is removed from an EventTarget while it is processing an event, it will not be triggered by the current actions. EventListeners can never be invoked after being removed.
Calling removeEventListener with arguments which do not identify any currently registered EventListener on the EventTarget has no effect.