The cv joint on the end of the shaft that slips into the knuckle/hub assembly has ball bearings and there is no way for it to simply pull apart and get stuck in an awkward position. On the other hand.....
The cv joint on the end of the shaft that clicks into the transmission has 3 'doughnut' shaped bearings that are mounted on a post. (3 posts, one doughnut bearing per post). If you tipped the knuckle away from the car, for what ever reason, there is a good chance that one of those doughnuts fell off its post and is preventing the cv shaft from sliding back into the cv bearing case.
The only way you will be able to figure this out is to pry the c/v out of the transmission.........remove the big ring clamp from the rubber cv boot and pull the cv bearing case off the cv shaft.........make sure each the three doughnuts are on a post and then slip the cv case back onto those three doughnuts. Replace the big clamp with a new one.
When you remove the cv from the transmission.......there will be some fluid that drips out, so be prepared.
Here is a pic with two of the doughnut bearings missing from thier mounting posts
Here is a pic of the cv case which is the side that clicks into the transmission.....and the three doughnuts and the cv boot....notice the clean ring around the big end of the cv boot, that is where the boot clamp has been removed: