There are 3 camps of liability with a case like this.
1) Most important - the consumer. Consumer buys a product, they better be getting on the computer and researching what they have purchased and what if any information they get from the vendor. Ultimately your safety is in your own hands, the end user, as there are products that need a heck of a lot of research to operate safely, not just common motions and notions, electronic vaporizers fall in this very category.
2) The Vendor - This here is also another issue that raises the hackles on the back of my neck. The greed of a lot of vendors. No warnings printed or such on some online vendor sites, physical vendors its almost like hearing a practiced quick spill script, do this, do this here, liquid here, close up, five clicks turn on, you vape. Very little 1 on 1 with new or inexperienced vapors with general knowledge. As a B&M employee I angle questions from the moment a customer walks in to gauge not only their experience and knowledge, but also what they are interested in. Replies and feed back I get helps me not only in the sale but what I need to impart to them if they are overly pressed for time, an hour of 1 on 1 with especially a new customer/vapor goes a long way in regards to safety but also improve their chances of quitting smoking/tobacco use. But there are owners/operators out there that have or are getting in to make a quick buck that don't do their research as well which can be a compounding factor.
3) The Manufacturer - Most manufacturers got their ducks in a row, these are pretty big companies financially, most products come with user manuals, certifications labeling and such on or in the packages. However when talking battery safety for instance, there are companies, in my opinion, that put their consumers at unnecessary risk, examples Efest, MXJO, Imren and several others by over specifying their battery capabilities that puts consumers in a false sense of safety level.
Seeing some of these case go to trial might help weed out some of these issues at the Manufacturer and Vendor levels by holding them at least partially liable, but not all liability should be taken off the Consumer's shoulders entirely, as stated above, the last line of safety and defense is mainly on the consumer's shoulders to learn to use what they buy safely and reliably.