That wording: "she jumped up" doesn't ring true to me. From accounts I've read where a victim has been stabbed and is feigning death in order to escape, those victims don't jump up and attack, they lay motionless, until the perp. leaves the area.
The wording almost makes it sound like the perp. is saying she attacked him, in order to say somehow she is involved--"life-threatening injuries".
The injuries he got apparently weren't life threatening enough to keep
him hospitalized for several days.