They used a fire extinguisher? What a g@y way to kill a snake.
James Bond used an aerosol deodorant can and cigar (to convert the aerosol can to a blow torch) to kill a snake in "Live and Let Die". A fire extinguisher is a good alternative, especially for when you don't know exactly where the snake is likely to strike from as you open the container where it is hiding and pissed off.