Fascinating Mike, very grateful for the info and I now have a much better understanding myself of the risks involved i can help explain to fellow photographers who are unaware or have very little understanding of the risks while photographing storms.
I certainly take too many risks and have had a few experiences as I am sure many, including yourself, have.
Also, I wanted to ask, you seem disappointed the flashes in both yours and Jacci's image are not positive, although you thought they were. Is that because they were close to the positive upper regions? was there no other way of telling?. Is it only the rarity of the capture or is there something else more important like the severity of the storm or amount of ice that makes a positive flash more significant?
Re the topic, I found two images taken of the same storm where it appears the lightning is striking in the same place.