That's effectively a fancy version of a regular garden-variety charcoal grill, isn't it?
Accidents with ignition fluid are dime i dozen with those. You douze the coals with fluid, set it on fire. Soon enough the flame smothers down for some reason, so you the slightly drunken moron go on to squirt some more ignition fluid which hits the hot metal of the grill, and a fireball ensues. This is your usual America's Funniest Homevideos stuff. I'm sure there are plenty of precedents in the courts too, because people get hurt. A person really should know better, so it's a point for there having been negligence.
This time around the flame (also) travelled back the fluid squirt and ignited the fluid bottle effectively making it a Molotov's cocktail that accidentally got thrown at the poor woman in her apparently flammable clothes. That's very bad luck, but it's also an immediate consequence of the negligence so it's probably hard to explain away as an out-of-nowhere accident having happened.
I understand also the fireplace maker and the ethanol provider companies are named as defendants, apparently for inadequate warnings. It's obvious enough that you shouldn't pour the fluid on hot metal, so you would expect there is a warning.
In our wacky world any lack of explicit warning for such an apparent risk could even be understood as the manufacturer's statement that the usual risk is not there with this particular product and that it's safe to add this particular fluid in a hot fireplace.
"I was aware of such risk generally being there, so I carefully read the bottle before doing this. From the lack of any kind of expected warning I assumed this was safe fuel to pour on a hot burner. As the bottle ignited in my hand I was first surprised and then aghasted of the extent of the criminal negligence by the [fluid manufacturer]."