The whole Halloween event has been crippled so badly for the past couple weeks, Blizzard should seriously consider extending the event for their faithful customers.
The Hallow's End event takes place between Oct 18 and Oct 31.
However, between Oct 18th and Oct 26th there was a nasty bug taking place. Players on all realms would freeze, disconnect, and crash when trying to summon the Headless Horseman. The same issue impacted battlegrounds and other "dreaded cogwheel" items that could normally be interacted with.
On Oct 26th, a new fix was implemented to correct the issues. However, it did even more harm. Immediately after the fix, BG/dungeon/event queues crashed and the HH event couldn't even be accessed anymore. Also, the Shade could not be summoned by the Matron in most locations for the "Putting Out the Fires" daily quests.
I don't even think the Halloween event was truly fixed until around Thursday the 28th. That really only leaved 3 actual days for the players to participate in the Hallow's End event. There have been no extension announcements so far and no free game time for the millions of players that were impacted or unable to participate in the event over the past couple weeks.
I'm not sure why it took so long to "fix" the issue, but I suspect it's because everyone at Blizzard was so busy with Blizzcon and their support staff were directed by Sr. Management to prioritize Blizzcon gaming events over everything else.