Still a very funny bit, with both Shattner and Palin doing a great job. Funniest thing on Conan since I don't know when.
Oh of course they were in on it, they did a great job. Shatner’s face was priceless. He did a great job, Sarah did an amazing job and loved the audience reaction
It was a very funny skit. Sarah has posted pictures on Facebook taken in the greenroom before the show. One has Shatner signing a copy of his book for her. He was in on the joke.
Keep in mind that the talk show host jumps to the tune of the show’s producer, who is basically a censor with the power to shut down broadcast if various decency or political thresholds are exceeded. They absolutely can pull surprises like this. I recall an old Steve Allen show (the original Tonight Show host) when a bucket of tarantulas was dumped on his chest during a “nature” segment. He was a) very surprised and b) not pleased.