Well the conclusion is not surprising. Bugs aren't found because many people "read" the source code, but many people of many different skills use it and therefo

Well the conclusion is not surprising. Bugs aren't found because many people "read" the source code, but many people of many different skills use it and therefore every problem that is hard to you will some day find a person that has the specific domain knowledge to fix it much more easily. Also I'm a little surprised at the size of the dataset and the choices, given that open source probably fixes an easier bug faster than a higher priority one.