When you send a 2-tick off pulse into a torch, the length of its output depends on two things:
a) which face of the block it is placed on
b) if there are other redstone torches attached to the same block
In the screenshots you can see my test setup with a simple clock at the bottom, feeding into a monostable circuit and a small torch tower.
If there are torches on all sides of the block, we see a 2-tick pulse on the repeater line facing west and 1-tick pulses on all the other lines. As soon as the 2-tick torch is removed, we get the 2-tick pulse on the opposite side (east). Remove that torch, and the top one will emit the 2-tick pulse etc. etc.
The order seems to be: west, east, top, north, south
This is the same bug as: https://mojang.atlassian.net/browse/MC-2340