I saw a fatal accident from 50' on an acceptable approach when the student and friend on her first flight in a single seater suddenly got messed up with the spoilers.

There's differences between an L-23 and a Junior that the student had not been briefed on.

Coming out of a vortex / downburst encounter on final, I missed a wire by just enough to avoid becoming a statistic.

You can establish margins, but Mother Nature at any time can blow right through them and put you into a totally new aerodynamic situation.

The operative word is blow.