Even if any questions were inappropriate, his attitude was disgraceful. .
I think that was the point the inane questions were to show his general demeanour and if he has a temper. It is used as a character witness and he showed himself to be vain, cocky, petulant, argumentative and a sense of entitlement. This will all be used against him. The questions actually served their purpose as they showed his true character. It's the littler questions that show the biggest answers in that sense.
The actual case is to do with violence so he has just shown himself in the worst light during questioning especially the aggression towards the person transcribing. It shows he has a low threshold for simple verbal exchange leading to aggression.
Apologies if this has been posted before but it's a lawyer explaining depositions what Justin did wrong and what he should have done.