I don't know if it is or isn't vacation abuse - remember that user has other games going as well - but my recommendation is to wait until your opponent is out of vacation time.
Also, you may get better results on adjudication if you file a ticket with the site instead of putting your request for adjudication in the forums. Whichever you find to be more successful, can you let me know either way (i.e. post here what works and what doesn't).
I'm in the third round of a tournament and my opponent went on vacation after entering into hopeless endgame. Is this considered vacation abuse, and if so, can a staff member end this game?
Here is the game:
http://www.chess.com/echess/game.html?id=41856751