I think you would be too preoccupied whilst executing an in water or underwater rescue to think of what a jury would think
But honestly, In my opinion, and being new to this, I think of every person I enter the water with as my brother or sister.
We are entering a hostile environment together.
I would never think for one second of what repercussions might follow a failed attempt at rescue.
In that moment, I will do what it takes to bring you back.
I have been a part of many rescues, two of which the diver did not make it.
I never was held responsible, admitedly the circumstances were different.
But I dont think I could get myself to act or think any different.
I find that reasonable (it's what I would do) and I bet most juries would find it reasonable as well.