That was my thought immediately, where is their sense of humour. To say it isn't funny is fair enough. One sees what the joke creator was trying for but it doesn't quite make it. But relating it to their specialist area as though it were insult rather than just the necessary setting for the joke, is oversensitivity at a high level.
I think they have embarrassed themselves and need to sit down and consider their overreaction. No one is mocking the actual issue of Tourette's syndrome, it's merely fertile ground for an innocuous jest.