That's the good and bad thing about 18650s. When you harvested your cell, it was probably the same as a puffed lipo, but you couldn't see it because of the steel case, and assumed it was like any other 18650. Charging it "puffed" it enough to disconnect the positive electrode. If it was a lipo, you could have had an explosion.
I have had 2 cells go CID during storage, and 1 while doing a (second) discharge test when I wasn't in the room.
One time I experienced the CID working in person while soldering high-drain cells for a high-drain pack, and it does make that "pats" sound. Either I left the soldering iron too long on the cell or some solder made its way to the negative part of the steel case. Three minutes after the CID triggered, an IR thermometer read the cell temperature as 113*C / 235*F. CID is nothing to mess with. Get rid of that cell, it has been compromised.