I felt that Nel had possibly reached a dead end with that line of questioning.
Everyone hearing OP's would think that OP's behaviour was neither logical or sensible, but that doesn't mean it couldn't possibly be true.
So Nel can be as Nelentless as he wants saying "That's illogical, it didn't happen", but if O.P insists it did, what then?
That there were no screams, or he couldn't hear a scream over the shots, or that he was shooting so quickly he wasn't listening for screams - all could be possible.
Yes, Nel can do his best to tie O.P up in knots with repetition and confusingly worded questions, but that would confuse and trip anyone up, regardless of the truth or not of their story.
I do not envy the judge's role at all.
OP's family were seen talking to the defence team, are there any restrictions on what they can discuss?