On the fatality issue:
The refrigerant gas does not support human life, if it displaced all the air in your car then you would not be able to breathe. However there are (were) only ounces of the stuff in yr system so that is not an issue.
However, exposed to a naked flame I know the old R12/R22 reacted to produce phosgene - not good. Not too sure about the new fangled ozone friendly gases R134 et al.
230 TE (W124) 1989 with 153,000 miles on the clock - hoping for at least another 100K