Alight, seems as though due to lack of sleep, and perhaps a
bit of sour grapes at being brushed off by openbsd over a
likely unrelated bug, I have managed to combine two unrelated
problems. It seems openbsd will reboot under the circumstances
described with any large ping. I have no evidence netbsd
exhibits the same behaviour.

It was while trying to reproduce a panic caused by the fragment
in the origional post that I stumbled onto the second reboot.

The bug still stands, but it's just that, a bug. Not an exploit.
If anyone wants code that reproduces it under net/openbsd feel
free to mail me with info on where to send it. (be polite:)