Aren't the probes still legally considered property? Given this, it follows that they cannot enter into any contractual agreement. So it's a moot point whether or not they sign it--it's not valid to begin with.
In any case, any response from the probes, be it "Okay, whatever. We'll sign it if you give us the codes," to "The wording of Paragraph 8, Subsection 2, Sentence 3 must be changed to include the phrase 'Parker and Hardon agree to turn around three times before sitting down at their desk each morning while reciting the phrase "I am a chocolate donut"'," is just going to prompt them to try more of this tactic. I go with the side that the "What was that? I'm confused," response is the appropriate one. Gail had no idea what they were talking about, and she should communicate that with them.
-Psiclops (NOT a lawyer!)