John:
If the "scissors"/trunnion link on a BT-13 breaks, the gear won't fold. What'll happen is the wheel will rotate around, kinda like that JetBlue Scarebus. That's preferable to the other potential, which is the lower leg departing the airplane.
With Art's Yak, I would *guess* that the upper mount broke, which on landing would allow the gear to fold back and under the airplane, rather than being cocked 90 degrees to direction of travel.
When ya gonna come get the rest of yer parts?????????? Bring a carryall with ya, I'll take care of it for ya!!