Well I think it's very common for representatives to not directly reply after a certain incident, because they don't have all the details yet and they want to take time to form a proper response. Don't see how this is specific to Trump.
Those are distinct, though potentially overlapping, behavioral patterns.
It was almost a meme on his last presidency. If there’s a scandal involving someone from inner circle - trump’s replies often were “I barely know him/her”/“Never met him/her”, etc.
Good examples and I believe that’s a Bill-Clinton-under-oath use of carnal “is”. Nobody has the patience to wonder whether it’s true or false that Trump knows of the existence of Putin. Bill Clinton didn’t get away with it, so I’m willing to say this is specific to Trump.