It seems that the tranquilizer darts do not contain any 'charge' or gunpowder that would allow them to fire from a nonmodified .22 rifle. It is the striking against the back of the bullet containing gun powder, by the rifle pin which causes the bullet to shoot out of the gun. It seems that dart guns are working off of air propulsion - like many bb or pellet guns. So while the caliber of the tranquilizer dart may be .22, it would not shoot out of a rifle that uses .22 caliber ammunition, because it is lacking the firing charge.
If Suzanne was 'shot' with a tranquilizer dart, it was most likely manually put into her and definitely not shot into her from that 'squirrel' .22 that Barry surrendered. JMO
The Tranq dart i researched based on the brand in the AA is indeed fired like a .22 bullet - i.e. not an airgun
I will see if I can find the product video later today
It is quite interesting. After the target is shot, a spring delivers the payload, then the needle drops out.