The reported delay time of 0.1s for a redstone torch is not always adhered to (again, this is a separate phenomenon from the North/South Quirk).
What I expected:
When redstone power is removed from the block that a redstone torch is sitting on, the torch turns on 0.1s later.
A redstone torch turned on instantly after the block it was sitting on stopped being powered.
Steps to reproduce:
I probably wouldn't have noticed the 0.1s difference if I hadn't been trying to make a song with note blocks.
1. Build what's shown in the attached picture. I recommend placing the note blocks on some kind of stone; the bass drum sound is ideal for our purposes. In case it's not clear, all repeaters are facing right, and the third, fourth, sixth, seventh, eighth and tenth from the left are on the second setting while the rest are on the fourth setting.
2. Flip the lever on and listen to the rhythm that the top row of note blocks produces. You should hear something reminiscent of a marching band: "bum bum bum-bum-bum bum-bum-bum-bum bum-bum." For the musically inclined, defining a quarter note as 0.4s, that's two quarter notes, two eighth notes, one quarter, four eighth, an eighth rest, an eighth note, and then a quarter note.
3. Flip the lever off and listen to the rhythm that the bottom row of note blocks produces. It should be far more erratic: "bum bum badum bum badum badum, badum." Again for the musically inclined, that's two quarter notes, two sixteenth notes, an eighth rest, a quarter note, two sixteenth notes, an eighth rest, two sixteenth notes, a quarter rest, and two more sixteenth notes. The difference is that on the bottom row, the fourth, seventh, ninth and eleventh note blocks are triggered 0.1s early. So it seems that the associated redstone torches took zero time to turn on upon having the power to the blocks they're placed on removed.
4. Place a door on top of each of the 11 stone blocks (wooden or iron doesn't matter). Flip the lever on (let the top row of note blocks finish) and off again, and notice that the doors not only open but also close in the rhythm of the top row. Since the doors aren't powered by the torches, this shows that the problem is not that the repeaters are producing the wrong delay "on a falling edge" (when turning off).
5. Break all the doors. Change the setting of the third repeater to 3, and the fourth to 1. Now, the top row still behaves as expected: the first five notes of it sound like "bum bum bum badum" (quarter, quarter, dotted eighth, sixteenth, quarter). If the bug was still present, the first five notes of the bottom row would now sound like what the top used to sound like, but instead both first-fives now sound the same. This indicates that the setting of the repeaters is relevant.
It looks like something involving having a repeater on the second setting connected to a redstone torch screws up the timing of the torch. I hope I was detailed enough to demonstrate this admittedly subtle issue.