My father had a similar incident, flying the Botha in England. On final, one of the checks was to check that the big sliding window of the roof was open. He reached up to feel for the window, and felt something really odd, a lot like a rubber tyre - he looked up and it was the undercarriage leg of another aircraft above him!
Being on final, he couldn't really dive away from it, but he nosed over and turned away from the runway - the aircraft clashed together. It damaged his vertical fin and one aileron, so he had big troubles with directional stability and was pretty much stuck in one direction - away from the airfield. (The other aircraft had a rough landing straight ahead, minus one wheel.)
Dad wrestled the aircraft ( Bpthas were famous for being underpowered and a handful at the best of times) at low level for a bit, but decided that once he crossed the next line of trees, he would put it down on whatever was there. It happened to be an airfield! Luck was with his crew that day.