This is the kind of IMBA thing that would be fixed in Dota the day after it is recognized by the playerbase. I'm not kidding, they make tiny balance patches constantly and imba stuff is never allowed to fuck up the game for very long. It sucks that this thing is having a huge influence on the War Paint tournament results. USF appears to be way OP right now, and this mortar is one of the key reasons.
This is correct. Also League of Legends disables a champion from time to time for 1-2 days if they notice a bug that affects only 0,01% of the games. Just a small bug e.g. where he/she can walk through other units in a very special angle that you probably will never be able to recreate.
0,01%!
While you can see the USF mortar in > 95% of games against the USF and even the biggest USF fanboys on this board say that it is broken right now.