I hope to shed some light on this by sharing what we know about the issue and solutions that we attempted.
Background: We have installed about 3000 of these Samsung locks (P718 and variants of these) since 2015 and we do sometimes get “I am locked inside” calls over the years. Installation experience matters much more so (for this “push-pull” lock from Samsung). versus the traditional turn lever type of digital locks.
Issues and solutions
Issue #1: Unable to unlock from inside when pulling the handle but manage to unlock after a few times. This is due to installation issue where there is friction between the bolt and the strike (on the door jamb). Temporary solution: push door in with one hand while pulling the Samsung handle. Proper Solution: Adjust the strike plate
Issue #2: Unable to unlock from inside when pulling the handle but unable to unlock even after many attempts. We do see cases where the *bolt* is jammed so even if you have the mechanical keys , you cannot unlock from outside (because the internal bolt mechanism) is jammed up. Solution: get a + screwdriver and remove the rear lock body and plate so that someone from outside can remove the outer body and exposing the mortise. Stick in a ‘-’ screw driver into the slit (where the ‘ice-cream stick’ like shaft was) and apply force to forcibly turn to retract the bolt (note: may require a lot of force).
Issue #3: (mystery): We have heard of some users who solved the above problems after replacing the batteries and there are some posts in this thread that mirrors our thinking, that the mortise bolt mechanism went into an ‘in-flight’ state (that prevents even a manual pull to unlock). Cases from this scenarios resolved itself and the problem did not repeat (to our knowledge after). The sensitity to “in-flight” power loss is a mystery (perhaps to the person who designed the mortise.