[Older Jason knows the younger must feel humiliated with how fast the takedown was. But at this point, he might as well emphasize that all the BatFamily members here can give as good as they can take. The younger Jason needs to know there's still a lot for him to learn]

You're not the only one who got trained. We all were.

[With that and with knowing he put a tracker on him, Jason lets him go. He's aware that the younger Jason might find the tracker soon enough but he might as well try to get another read on him. Or at least broadcast to the kid that this isn't going to go down easy for him]