^Interesting question. I don't think so because both he and Kirk already seemed to have an idea of Valeris' involvement in the conspiracy (Kirk's log entry being used at trial; Valeris' questions to Spock about turning points). Spock didn't seem surprised that Valeris had come to sickbay to kill the crewmen but disappointed. That could suggest Spock would have prepared for his death ahead of time, but I think his statement about Valeris shooting him because it was logical that she follow through on what she'd committed to was more an observation than it was a dare. He already knew she wouldn't do it.
That is my impression as well.