I've always been disturbed by the hesitation he shows before the jump. You can see him psyching himself up for it, but at the last moment, he seems to go weak in the knees and just tips off, falling almost vertically.
You have to give him credit for bravery, but I have to wonder if he did any tests with a dummy.
Considering the first successful parachute was demonstrated in 1783, (http://en.wikipedia.org/wiki/Louis-S%C3%A9bastien_Lenormand) Franz had more than 100 years of experience to draw on.