Board Thread:General Discussion/@comment-26208943-20150224183255/@comment-26205636-20150315155626

Steven normally has a  hard time controlling lion who generally generally does whatever it wants which usually is to protect Steve in some way (i.e. in the episode, Rose's Scabbard, Lion did not even respond to Steve calling it by name) so one of the few times, it actually does listen to Steve is when he tells it to stay behind even though it puts Steven in semi-mortal danger. The only plausible explanations are like you said it chose that moment to listen to Steven (despite Garnet and the other gems being defeated and, Steven being knocked unconscious then abducted right in front of Lion) or it believed that Steven matured to the point that gems like Jasper and Peridot were not a true threat. Lion generally acts in a way that protects Steven while at the same time fostering his growth and maturity kinda like a mother ;P.

That said 3. in my last comment was just a side tangent that had nothing to do with my belief that Steven's gem is Rose's body while Lion is her soul.