I think Trump cannot conceive of Putin disrespecting him, and/or he can't afford to give space to the concept. It was a good question.

He’s too old and not mentally agile enough to hide the thought process taking place after he heard the question.

“Mustn’t insult my boss”.

When confused and clueless throw insults instead of answers. Trump’s strategy for years.

I know. Unwilling to risk their access as it represents their livelihood, at the expense of their integrity and reputation. I suppose someone has to be present to verify the lies told.

This is the most telling response to show that he works for Putin.

Pretends not to hear - when that doesn't work, and once Putin is criticised he shuts down the critic.