It is my understanding that the lock is not the issue - but overzealous LEOs gravity dropping the knife is. If you flick it open with a very hard snap, or if you can grab the blade and snap it hard enough that it opens, they can call it a gravity knife, and you just might have an appointment with a judge. Most Spydercos can be opened this way.
And it is true that you can't have any part of it visible.
At the risk of turning this into a "Knife Laws" thread, NYS defines a gravity knife as:
5. "Gravity knife" means any knife which has a blade which is released
from the handle or sheath thereof by the force of gravity or the
application of centrifugal force which, when released, is locked in
place by means of a button, spring, lever or other device.
http://ypdcrime.com/penal.law/article265.htm
So the lock DOES have some significance if the LEO can flick open your knife and it locks open. Which is why I might consider the UKPK instead of the Caly 3. The debate in my head (among others