I'm guessing once it starts 'stinging' he stops shining it at his hand... Anyway the movie laser burned instantly down to at least blood and possibly to the bone and it was moving quickly because it left a red swirly mark on her hand..
At least now people get afraid of 5mW, that may just help people forget the idea that lasers are just simple toys.
An excimer laser used in normal lasik procedures is pulsed and far is the uv, so invisible. It actually has a map of the eye where to remove tissue and it tracks the eye if it moves. Quite sophisticated.
Every piece of medical equipment makes a loud hammering noise... Is that some sort of FDA requirement? X-ray machines, MRIs, Surgical lasers... what gives? Do they have to add a special "bang making" module?
Maybe there is a midget with a hammer trapped inside and when they turn the machine on he gets zapped and he's just trying to escape?