What are the best techniques to show a character panicking as it is seen by the POV character?
So the problem I am having is that the protagonist of the novel I am writing is having a confrontation with another character, who starts panicking. Instead of saying "panic dripped from his face", I am trying to figure out a way to rewrite this so that it shows, not tells, the emotion. This is difficult for me because the story is told from the protagonist's point of view, which means he is observing the panic, not experiencing it himself.
What are the best techniques to "show instead of tell" this character's emotion through the observer's point of view?