bulleo*edit - I was wrong. Thanks kennyj. Saw a video that showed it just helps hold it open.
Looks like it locks based on the center of the frame. That middle tab probably locks in place when opened.
Ridiculous that a safety feature is illegal, but we have a lot of stupid laws as well.
StormTrooperIt's just a detent; meaning it holds the blade open, but it's not a lock per se. If you can have a slipjoint, then I'd expect this to be fine. I'd suggest looking for a video review of the knife, see how it works, and draw your own conclusions.