What would be the scenario wherein a pod hanging from a tether would provide a means for Finney to get out and get back into the ship without any witnesses assisting? Did he have a personal transporter that didn't mind ion storms?
If the pod were deployed, then retreived, and then
jettisoned, we should be having lots and lots of dialogue on the reeling-out and reeling-in action. This would be far more crucial than possible jettison commands.