Page 10 of the manual says the slide does not lock open upon firing the last round.
"Manual Slide Hold Open: This allows the user to manually lock the slide open.
Note: when the last shot has been fired and the magazine is empty, the hold
open does not automatically hold the slide open. If a loaded magazine is inserted
in the pistol when the slide is closed and the slide is then retracted fully, the
slide hold open will not automatically hold open the slide. The user can actuate
the slide stop mechanism to hold the slide open at any time by retracting the
slide and pushing the slide hold open up."
Bold emphasis added.