Jason once made the mistake of telling Damian that he ‘didn’t trust him any further than he could throw him.’
Damian was heartbroken.
Jason was suddenly snapped back from offhanded snark and was awkwardly repentant.
However…it’s Damian. Once you make a slip like that, it sticks. So, to prove to Damian that he did actually trust him, Jason’s only logical recompense was clearly to throw the kid as hard and as far as he could. He tried to select a soft enough surface to prevent permanent damage.
Explaining the sprained wrist to Alfred was not fun. And claiming it was ‘family bonding to help prove and internalize Damian’s worth and self-esteem’ didn’t help much, either.