Can you provide more information or link to the article with information regarding your situation?
Because V-SYNC works by motior waiting for full frame to be rendered and at least one frame in buffer, thus adding latency. That's the whole point.
Maybe your game runs at Borderlees Fulscreen or windowed mode? Because those are tripple-buffer v-sync'ed in Windows.
Better use RivaTuner and it's scanline-sync feature. It's 100% lag-free but you need more "free" GPU time for tearing to not appear. I used it all the time when on old monitors ESPECIALLY in 30fps games. Rivatuner have scanline sync/2 mode which is half of the refresh rate.
I ran it full screen with vsync on and I used the frame limiter built into Rocket League. 59fps felt the same as having vsync off, except there was no tearing at the expense of having to deal with the stutter of not matching the display refresh rate. Rocket League must be triple-buffered.
Actually, I can't remember the last time a game used double-buffered vsync. It seemed like all of my games could drop below 60fps without tearing while vsync was active and they didn't drop immediately to 30fps like a classic double-buffered game.
Anyways, when I got a FreeSync display, I used to set all of my games to be capped at 141fps to stay within the FreeSync range of 144Hz, therefore my games wouldn't stutter or tear no matter what happened with the frame rate. However, I still kept vsync on and as long as the frame rate didn't hit 144, I wouldn't have any input lag (it's essentially the same as vsync off).
As you can see from this graph:
...it doesn't really make a difference having vsync on or off (in regards to input lag), but it does make a difference by capping your frame rate to something lower than the max refresh rate of your display.
I go the graph from this video:
in the 3rd and 4th graph, vsync on vs off difference is within margin of error and wouldn't make a real world difference.
You also lower your input lag by making sure your GPU load isn't being maxed out.