It seems likely to me that assault isn't involved in this at all, it's just illegal to buy or administer anesthetics without a medical license.
Why is it illegal to buy or administer anesthetics without a medical license? Just defending the monopoly or is there some legitimate reason?
http://www.theverge.com/2012/8/8/3177438/cyborg-america-biohackers-grinders-body-hackers