MMA a legal weapon?

[sanjuro_ronin]

but then for non professionals, how do you gague whether or not that person is actually profecient enough with their MA to even be that 'deadly'. people die in altercations against non trained people as well, so i could see it being a tricky situation. what if the guy that punches and accidentally kills a guy just had some weird luck but actually SUCKS at martial arts?

One could perhaps gauge based on the damage done but that is highly subjective of course.
A professional fighter is viewed in a far different way than a recreational practitioner of a given MA, much like a professional driver's skill is viewed in a different way to that of the recreational driver.
IF one is going to state that a MA practitioners skill can be viewed as a "lethal weapon" then one must define not only "lethal weapon" under the context of empty hands BUT also define WHICH MA fall under that category.