Problem: If "Pam's parents came home and found her having sex with her boyfriend, Paul. They were furious about it.", is "Pam and Paul were furious about it." correct?

Answer: no


Problem: If "The foxes are getting in at night and attacking the chickens. I shall have to guard them.", is "I shall have to guard The chickens." correct?

Answer: yes


Problem: If "I couldn't find a spoon, so I tried using a pen to stir my coffee. But that turned out to be a bad idea, because it got full of ink.", is "The pen got full of ink." correct?

Answer:
no