Balloons and parachutes don't change direction in midair and move quickly with incredible speed. They also don't land and then take off again leaving swirled circles in the grass that military personel scan with geiger counters and then burn a week later. They also don't vanish in midair.
Balloons that are descending in an uncontrolled manner do bounce - or are at least capable of it. If they are descending at a reasonable speed due to entering, say, a localised low pressure volume (the way aircraft can suddenly do), then they will retain that downward speed when they leave it, despite possibly having a net upward acceleration in the higher pressure air (so they'll be slowing down as they get lower). Thus, they can hit the ground and then the upward acceleration will result in the balloon lifting up again. Local winds could even keep the balloon at ground level for a while, blowing it around, before it lifts up again.
Simple physics, really.
It might also explain the changes of direction - although I don't know the local wind-patterns.
As for the swirled circles in the grass - again entirely possible if the balloon is close to the ground and being swirled around while dragging a payload.
As for the geiger counter - if this was, as suspected by many, part of the HIBAL program which was investigating radiation levels after the Maralinga nuclear tests, the military personnel would be all over it with such things, and depending on their findings they might well burn the affected areas.
The record of flight 292 might have been "removed" as an attempt to cover up that a radioactive balloon (if it had picked up radiation) crashed near a school. Or the records were simply misplaced as a result of continual investigations into them, requiring the paperwork to be handed around. But I can't say for sure, of course.
As for your own analysis - on what do you base the % you have used?
Further, the analysis can only lead to dubious conclusions.
Let me demonstrate:
What are the chances that a person's great grand-parents never met... let's say 1 in 2 (50%) - it was perhaps a chance encounter at a bus-stop.
What are the chances that they actually liked each other... let's say 1 in 2 (50%)
That they fell in love? 1 in 100?
That their child would have exactly the characteristics of the one they had, given the millions of different sperm etc...
You do this at a simplistic level for a few generations and you quickly conclude that each and every one of us has a non-zero but ridiculously small chance of ever existing... such that you would probably conclude we can't exist. And yet here we are.
Simples.
Not saying you're necessarily wrong in your assertion of it being a UFO, just that I find the HIBAL explanation to be vastly more compelling.
