LOL. There is no one-way lead barrier or EM barrier.
EM or TP waves travel both ways. This is a fundamental law of Physics.
The writer apparently didn't know he made a boo-boo and forgot that Jean can't use her TP as well.
Look at it another way, is there a sound barrier that only blocks incoming but not outgoing? Your earplug blocks incoming waves but it should block outgoing sound if you were to use your earplugs in your mouth.