You were recently insulted by a person whom now stands in a welcome line. Would you shake his hand or ignore him?
I would shake his hand but with a look that let them know that I was a bigger person by doing so and don't even say or a word or I might just forget that and let loose..in other words, shake my hand, shut up, and move on.
tRump at Bush's funeral. No, I do not shake his hand. But I wish Michelle would have squeezed and brought him to his knees. Would have made my week.
I would greet them and shake their hand. My manners do not require liking or respecting somebody.
^^Winner
Shake his hand, then publically disinfect it.
Depends on the insult. Was it deliberate, and out of spite or because of something else. I might just look them in the eye, stoic, and not shake their hands. Letting them know that I "recognize" them, but do not "acknowledge" them.
^^Runner up