I've often thought it odd that the J32 just has a curtain separating the flight crew from pax. The J41 has a lockable door, so why no changes made to the smaller version, especially since 9/11? Let me guess - money perhaps?
You still have the potential for this sort of thing to happen, whether it's 19 pax or 29.
In my personal opinion, if you give someone of this mentallity half a chance, they'll take it - so don't even give them the opportunity.
PS, Dysag - lol!
