The guy puts the phone next to his ear and tries to get someone to answer him. In the meantime, AGAG advises John to recite the planets of the solar system. "What?! How will that help me right now?!", John thought. "Might as well, though, you know best", he concludes.
He calms down, reminds himself the planets in his head and begins to recite the planets to the caller. In the meantime, just as he gets an answer and replies: "Hello? I found a guy here, trapped in the contaminated zoo--" He puts down the phone and asks John quietly: "What's your name again?"
(You have a skill for that. Rolled 54. Needs 50-100 to succeed)
"Mercury, Venus, Earth, Mars, Saturn, Uranus, Neptune!" John shouts to the caller, as his face turns from concerned to horrified. "Hello? Who's talking there?", John hears a voice from the phone. "Uh, no one, just...", the caller tries to direct the conversation away from John, who then behaved like nothing had happened. The caller continues the call, and mutters silently: "There's a crazy dude here trapped in the contaminated zoo, you have to do something!". The conversation continues for a few minutes, after which he puts his phone back in his pocket.
"Right, listen, man, there'll... There's gonna be an ambulance here soon, just... Keep your cool." He said stressfully, and ran away.