You couldn't outsource during crunch though. You'd spend all your time getting new people up to speed and waste way more time.
If you want to dig a hole out in the field and hire 3 people to do it, you can hire more and do it faster. Coding doesn't work that way.
Crunch happens because the people who are really good at what they are doing can only work so fast. You're already working with existing tools and a code base, someone coming in brand new (no matter how skilled they are) is going to be lost at first.
We've got code bases where I work where maybe 3-4 people really understand it. It isn't that the code is complicated, but all the interaction is really complex.
You'd never see new coders brought in late on a project. When that happens, it is earlier on (and shows that they are way, way behind).