These are Tool-Assisted Speedruns. That means that it's a human player using things like slow motion, mem dumps and other mechanisms to play perfect games. It's more an example of human's abilities when augmented with computers than AI discovering those glitches itself.
The most amazing run I've seen so far was a RTA (realtime time attack) of mega man 2. A human player is manually collision glitching and writing over memory with a sequence of inputs. And the RTA time in 2016 is now faster than the initial TAS records.
Do you have a link? Sounds like it'd be a very interesting watch.
Edit: I found one that has an example (I think) around 7:38 http://www.nicovideo.jp.am/watch/sm13963118 - the collision detection pushes megaman into the wall and jumps between different sections. Very interesting indeed!
Also you might be interested in the Final Fantasy 6 memory overwrite bug that was discovered in 2016 as well. It uses the Window Color menu settings as the data reference.
